It's relatively easy to remove the key for engine kill in the mod files, however due to it being clientside it could easily be reenabled by anyone with a little modding knowledge.
An exe hack to disable it would be fairly easy for those in the know, I believe.
I for one, support it. I only use it out of necessity, most of the time, and having a toggleable physics key is sorta dumb. I think a lack of EK would work well for Disco.
I say this as someone working on a mod with more realistic physics, so I'm fairly without bias here.:P