No. The game variant data is uploaded to the file share. As I said earlier, the tweaking data is stored within the game variant, but it's not something they 'hard code' via their script. It's data in the same vain as player traits or loadout settings, except there's nothing that exposes the ability to edit this data like you can with say Flag Carrier Traits.

Any time you change an option for a game variant in the in-game editor, you've essentially modded the game variant. The tools that I make just expose data which is not normally shown in the in-game variant editor. So using such tools would be modding a variant using unofficial means, which I'm sure goes against the terms or use, or at the very least is some gray area.

The weapon tweaks housed within a variant are only active while playing that exact variant. You can't play a variant with the DMR's damage set to 0, leave, then go into MM and start herp derping everyone with a BR while their DMR shots do nothing to you. The tweaks from that earlier variant won't be active. This is what I mean when I say you can't cheat with a game variant. It's all per-match, nothing global.