IMO there is no reason why the user should not be able to resize a control, just because one of the affected properties is selected in OI.
I have not been able to reproduce this in Lazarus, and have never seen such behaviour in any of the (ancient) Delphi versions I have owned.
(Lazarus 1.9.0 r57422 FPC 3.0.4 i386-win32-win32/win64 32-bit fpc/Lazarus on on Win10-64)
Bart