I agree and I’m not sure that, if it’s a good idea or not…
Especialy when you only have 1 parameter available:
I personally prefer to have everything visible instead of clicking everywhere to search for something.
Also, it means that if collapsed/expanded mode is implemented:
– last user choice (collapsed/expanded) should be kept in memory, even if Krita is restarted…
– for consistency all dockers should try to follow the same UI design (for example this one, there’s no collapse/expand for options in redesign)
Something I’m afraid of is many of users asking for help here don’t even know how to check the tool option docker; and when asking for screenshot, it’s sometimes hard to get complete vision of what is defined in options 
Having collapsed option won’t help us 
Something disturbing:
The fast mode is in a “level 2 collapse section”, but have impact on “level 1 collapse section”
Not sure that’s really good 
The fast mode should be at top level in this case, no?
(Sorry, my feedback is more on things on which I don’t feel comfortable in UI than the good things )
Grum999