diff --git a/Cargo.lock b/Cargo.lock
index 42be7cf9..93225764 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -72,7 +72,7 @@ checksum = "366ffbaa4442f4684d91e2cd7c5ea7c4ed8add41959a31447066e279e432b618"
 [[package]]
 name = "acadrust"
 version = "0.4.1"
-source = "git+https://github.com/ramox81/cadcodec.git?rev=4f929bd#4f929bda328b2024eb408b69e70d5fc80a8b22ef"
+source = "git+https://github.com/ramox81/cadcodec.git?rev=1eeab52#1eeab52a4e743816e5974e1e6441422b5042001d"
 dependencies = [
  "ahash 0.8.12",
  "anyhow",
@@ -878,7 +878,7 @@ checksum = "fc652a48c352aef3ea3aed32080501cf3ef6ed5da78602a020c991775b0aff04"
 [[package]]
 name = "cadkernel"
 version = "0.1.0"
-source = "git+https://github.com/ramox81/cadkernel.git?rev=33fd678#33fd678578de7d47c913121f147382c9d73d7830"
+source = "git+https://github.com/ramox81/cadkernel.git?rev=50c2551#50c2551d6bd46d19cfa664384bdc312b424269c4"
 dependencies = [
  "acadrust",
  "cavalier_contours",
diff --git a/Cargo.toml b/Cargo.toml
index 00680472..0182714c 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -27,8 +27,8 @@ glam = { version = "0.33", features = ["bytemuck"] }
 rfd = "0.17"
 clap = { version = "4", features = ["derive"] }
 env_logger = "0.11"
-acadrust = { git = "https://github.com/ramox81/cadcodec.git", rev = "4f929bd", features = ["serde"] }
-cadkernel = { git = "https://github.com/ramox81/cadkernel.git", rev = "33fd678", features = ["acis", "offset"] }
+acadrust = { git = "https://github.com/ramox81/cadcodec.git", rev = "1eeab52", features = ["serde"] }
+cadkernel = { git = "https://github.com/ramox81/cadkernel.git", rev = "50c2551", features = ["acis", "offset"] }
 dwg-thumbnailer = { path = "crates/dwg-thumbnailer" }
 flate2 = "1"
 image = { version = "0.25", default-features = false, features = ["png", "jpeg", "bmp", "tiff"] }
diff --git a/crates/ocs_plugin_api/Cargo.toml b/crates/ocs_plugin_api/Cargo.toml
index 51717d04..d5ec1fb6 100644
--- a/crates/ocs_plugin_api/Cargo.toml
+++ b/crates/ocs_plugin_api/Cargo.toml
@@ -14,7 +14,7 @@ serde = { version = "1", features = ["derive"] }
 # Pulled in only by the `host` feature, which adds the `acadrust`-typed
 # `HostApi` runtime surface. The default crate stays dependency-free so engine
 # crates and external tooling can depend on the manifest/ribbon contract cheaply.
-acadrust = { git = "https://github.com/ramox81/cadcodec.git", rev = "4f929bd", optional = true, features = ["serde"] }
+acadrust = { git = "https://github.com/ramox81/cadcodec.git", rev = "1eeab52", optional = true, features = ["serde"] }
 
 # Runtime IPC and serialization (host feature only).
 interprocess = { version = "2", optional = true }
@@ -37,7 +37,7 @@ serde_json = "1"
 serde = { version = "1", features = ["derive"] }
 cargo-lock = "11"
 # acadrust is scanned at build time to generate the embedded type registry.
-acadrust = { git = "https://github.com/ramox81/cadcodec.git", rev = "4f929bd", features = ["serde"] }
+acadrust = { git = "https://github.com/ramox81/cadcodec.git", rev = "1eeab52", features = ["serde"] }
 
 [dev-dependencies]
 serde_json = "1"
diff --git a/crates/ocs_web_worker/Cargo.toml b/crates/ocs_web_worker/Cargo.toml
index 1625721c..3d662239 100644
--- a/crates/ocs_web_worker/Cargo.toml
+++ b/crates/ocs_web_worker/Cargo.toml
@@ -8,7 +8,7 @@ publish = false
 crate-type = ["cdylib"]
 
 [dependencies]
-acadrust = { git = "https://github.com/ramox81/cadcodec.git", rev = "4f929bd", features = ["serde"] }
+acadrust = { git = "https://github.com/ramox81/cadcodec.git", rev = "1eeab52", features = ["serde"] }
 bincode = "1.3"
 serde = { version = "1", features = ["derive"] }
 console_error_panic_hook = "0.1"
diff --git a/crates/plugin-template-api2/Cargo.toml b/crates/plugin-template-api2/Cargo.toml
index a288337a..365b8014 100644
--- a/crates/plugin-template-api2/Cargo.toml
+++ b/crates/plugin-template-api2/Cargo.toml
@@ -10,4 +10,4 @@ crate-type = ["cdylib"]
 
 [dependencies]
 ocs_plugin_api = { path = "../ocs_plugin_api", features = ["host"] }
-acadrust = { git = "https://github.com/ramox81/cadcodec.git", rev = "4f929bd", features = ["serde"] }
+acadrust = { git = "https://github.com/ramox81/cadcodec.git", rev = "1eeab52", features = ["serde"] }
diff --git a/src/scene/centerline.rs b/src/scene/centerline.rs
index bdb55bfb..3c8d699d 100644
--- a/src/scene/centerline.rs
+++ b/src/scene/centerline.rs
@@ -24,7 +24,7 @@ impl Default for CenterLineSettings {
         Self {
             extension: 0.12,
             layer: "Current".to_owned(),
-            linetype: "CENTER".to_owned(),
+            linetype: "CENTER2".to_owned(),
             linetype_scale: 1.0,
             linetype_file: String::new(),
         }
@@ -206,7 +206,10 @@ pub(crate) fn construct_line(
 
 impl Scene {
     pub(crate) fn centerline_settings(&self) -> CenterLineSettings {
-        let defaults = CenterLineSettings::default();
+        let mut defaults = CenterLineSettings::default();
+        if matches!(self.document.header.insertion_units, 4..=7 | 11..=17) {
+            defaults.extension = 3.5;
+        }
         let Some(layout) = self.current_layout_object_handle() else { return defaults; };
         let Some(record) = self.document.xrecord(layout, SETTINGS_RECORD) else { return defaults; };
         let value = |code| record.entries.iter().find(|entry| entry.code == code).map(|entry| &entry.value);
@@ -251,8 +254,8 @@ impl Scene {
             "CENTERLAYER" => (1, XRecordValue::String(value.to_owned()), value.to_owned()),
             "CENTERLTYPE" => (2, XRecordValue::String(value.to_owned()), value.to_owned()),
             "CENTERLTSCALE" => {
-                let number = value.parse::<f64>().map_err(|_| "CENTERLTSCALE requires a positive number.".to_owned())?;
-                if !number.is_finite() || number <= 0.0 { return Err("CENTERLTSCALE requires a positive number.".to_owned()); }
+                let number = value.parse::<f64>().map_err(|_| "CENTERLTSCALE requires a non-zero number.".to_owned())?;
+                if !number.is_finite() || number == 0.0 { return Err("CENTERLTSCALE requires a non-zero number.".to_owned()); }
                 (41, XRecordValue::Double(number), number.to_string())
             }
             "CENTERLTYPEFILE" => (3, XRecordValue::String(value.to_owned()), value.to_owned()),