I found this technique on the internet, by which you can activate the in-game official (Ubisoft's hidden feature) God Mode and Unlimited Ammo, by making some changes in a text file of the Game.

All you have to do is go to My Documents > My Games > Far Cry 4 > Player and then Open GamerProfile.txt, find the line "<GameProfile />" and change it to "<GameProfile UnlimitedAmmo="1" GodMode="1"/>".

Please reply if I can do a speedrun with this developer's feature.

yes, you can, but we will consider it as cheat%

I find this theory of you speedruners very uneasy. "You can do a speedrun with glitches, but not with cheats, of which the former is more obvious or intended by the developer."

Thats just how speedrunning goes. Glitches are in the game no matter what you do, but turning on godmode and max ammo is completely different.

Glitches can be experienced by anyone playing the game, but what you are talking about is changing things in the gamefiles before even playing. That is something completely different and I dont see what the fun is even in that.

But to answer: changing things in the gamefiles is not allowed in speedrunning (unless a seperate rule is in place for exceptions.) Glitches can be used during the non glitchless categories of speedrunning.

The developers didnt intend for glitches to be in the game just as they didnt intend people to turn on godmode during the game.

I dont know what you mean with "Ubisofts hidden feature" but that is not a feature, that is just changing things in the gamefiles, this can be done for a lot of games, nothing "feature", I think you might be seeing things incorrectly.