I think there's a fair amount of issues with a config-only solution, but notably:
Many patches out there for Kerbalism that can only assume you're using a Kerbalism feature that causes incompatibility with whatever mod the patch originates from
There's still a fair amount of code running in the background for features that are disabled via Config
Over the last week I've actually been dissecting and cannibalizing Kerbalism as a fork to provide a proper "Science Only" mod, https://github.com/Twinki14/Kerbalism
The idea is to just have Kerbalism Science and allow for other mods to do their own background simulation of resource harvesting/manufacturing chains or life support, so that we as mod-users can sorta "opt-into" what we want instead of Kerbalism being one gigantic mod that overhauls so many key aspects of the game.
Currently,
All features except Radiation and Science have been outright removed on a Config level and Code level
Radiation has been kept, however it's strictly only used for Science benefits (Geiger Counter, Experiments that require min/max radiation or Radiation biomes)
However, the Kerbalism Science component on it's own heavily relies on custom CommNet logic and Electric Charge background simulation. Making it really hard to provide a "Science Only" mod and open support with other life support mods even though the Life Support features have been gutted strictly due to the Electric Charge custom simulation. Though, I guess with only Science Experiments being the sole feature in a Kerbalism fork that drains EC, it might be pretty easy to add external life-support mod support.