So according to this you're forcing Engineers to use a Grenade weapon to use Demolitions perk actions? I guess that means a bunch of Engineers are gonna save a bunch of perks after that unless you actually add a weapon that's WORTH SOMETHING that is a Grenade weapon.
The only thing that, as far as I know, made Demolitions even half-usable a line for Engies was that it DIDN'T require a Grenade weapon to be used. But that change to Creative Mind, I like. Medallion might even become landable now!
(EDIT: Only mentioning those perklines because Gadgeteer seems to stay in the useless range even if its procs are fixed and Mechanic didn't really get any changes, except some execution time reductions.)