8.0RC2 Cannot add 'thermal' flag to device instance line

Description

In the project attached, a VDMOS model is used for the transistor, enabling simulation of its power dissipation (thermal simulation in addition to electrical). This requires that the 'thermal' flag is set on the device instance line. The flag may be set during attaching the model, however when a simulation is to be run, Eeschema bailes out with an error message

The 'thermal' indeed does not contain an '=' sign, but is a completely valid (and necessary) flag. So the test for '=' seems to be wrong.

This error prevents me from translating several KiCad6 examples to KiCad8. VDMOS-thermal.7z

Steps to reproduce

1. Open the project attached
2. Double click onto Q1 symbol.
3. Simulation Model...
4. Attach model IRFP240 from file VDMOS_models.lib
5. In Parameters-->Flags set 'Thermal model switch' to ON
6. Inspiect-->Simulator-->Run simulation: Error message

KiCad Version

Application: KiCad Schematic Editor x64 on x64

Version: 8.0.0-rc2-328-g4a1245e85a, release build

Libraries:
	wxWidgets 3.2.4
	FreeType 2.12.1
	HarfBuzz 8.3.0
	FontConfig 2.14.2
	libcurl/8.5.0-DEV Schannel zlib/1.3

Platform: Windows 10 (build 19045), 64-bit edition, 64 bit, Little endian, wxMSW

Build Info:
	Date: Feb  2 2024 06:18:18
	wxWidgets: 3.2.4 (wchar_t,wx containers)
	Boost: 1.83.0
	OCC: 7.7.1
	Curl: 8.5.0-DEV
	ngspice: 42
	Compiler: Visual C++ 1936 without C++ ABI

Build settings: