Yes, there were some - I have now dug deeper into exactly what they were, so here you go...
Beta 9
Feather: General scoping problems with methods/constructors/inheritance
Feather: No auto-complete suggestions are shown for named functions after their dot is typed
Feather: Overlapping tooltips can occur for autocomplete, JS doc content, and rules [there is an improvement for this one, but not the final fix]
Feather: Cannot call functions directly off a new expression (e.g. new CtorFunc().func())
Feather: Various fixes for pure functions and matrices - this one affected a LOT of functions, so I am not going to list them all here, but there are some specific ones which changed in a more visible manner:
camera_get_proj_mat(), camera_get_view_mat(), camera_set_proj_mat(), and camera_set_view_mat() all have a returnType now of "array"
vertex_submit() now also allows passing in a real for its texture
network_set_config() now expects a constant for a specific network configuration, rather than a generic string
network_set_timeout()'s "type" value now expects a Constant.ExternalArgumentType value
fx_set_parameter()'s "type" now expects a real or any array, rather than a string or an array
And we fixed the two in-built constants "dll_cdecl" and "dll_stdcall" so their class is given as "ExternalCallType" rather than "ExternalCall"
Beta 10
Code Editor: Calling an inherited constructor which has optional args will throw error if you try to call it via ,, to skip an arg [note that this is only fixed in this version if Feather is enabled - if Feather is disabled, then the fix for that bit is coming in the first Feb beta]
Feather: "Feather Messages" window reappears, but is empty when Feather is disabled but opened a project which previously had Feather enabled in
Feather: Weak reference struct's "ref" variable is not detected as a built-in variable
Feather: Allow for a rule's severity to be changed from right-click context menu in Feather Messages window
Feather: Images in the Feather Messages "Resource" column are low quality [also fixed a memory leak caused by how Feather was loading these images]
Feather: Dependency Walker debug text is still enabled in the Output panel
Feather: Error trying to call function stored in variable, even though it correctly infers the variable as a function
Feather: Unexpected errors GM1046 "Reference to non-existent 'Resource'" when checking arguments in static constructor functions
Feather: Calling functions by extra brackets on the return value of another gives unexpected error "GM1053 The left hand side cannot be called in this way." - e.g. "variable_struct_get(...)();"
Preferences: Incorrect heading for Feather's Room Naming Rules - currently just says "Room"
Preferences: [Feather] Changing colours on the highlighting panel does not take effect until project is reopened
Preferences: [Feather] "color" in Highlighting preferences should be in UK English to match rest of the IDE
Preferences: Feather's "Message Severity" settings are always shown in random order
Fixed structs not adding fields through [$ operator.
Fixed incorrect marking of 'return types differ'.
Fixed array types not marking their types correctly for subsequent assignments
path_start()'s "endaction" argument was expecting an incorrect type
effect_create_above()'s "kind" argument was expecting an incorrect type