Hi Thomas, thank you for helping.
Althought, if I do:
Style * MaxWindowSize 50 50
Windows look fine, but my taskbar (managed with FvwmButtons) reduces to half horizontal screen.
With:
Style * MinWindowSize 50 50
my taskbar grows to half vertical screen.
Same issues with FvwmPager, so MaxWindowSize and MinWindowSize affect Modules.
UseSkipList is WindowList 's parameter and exclude modules from WindowList module, but
Style * UseSkipList
changes nothing.