ProMods

I am using promods and it has been a very satisfying experience.
Recently I am tampering with mods, so I got some questions:
-The promods cabin accessories pack: is it compatible with SiSL's Mega Pack?
I can load both mods simultenously in game but I want to be sure.
-I want to change vegetation drawing distance in def file. Is it safe to overwrite the old def with the new one?
Any help would be appreciated

1) I already load both mods many times, I think it's compatible
2) You can overwrite the old def with the new one for test. I that don't work good, just redownload a new def file.