Character experience editing would be a great thing to request, since nobody can figure it out with cosmos!
Please use the trainer option request system for requesting new options be added to this trainer and/or vote on options already requested.
While waiting for an update to be released, you can use our free CoSMOS Gamehacking Tool to easily hack the game yourself. We have tons of video tutorials available for even those with no prior experience with memory scanners or gamehacking tools.
In the game's data files, specifically in Steam\SteamApps\common\BATTLETECH\BattleTech_Data\StreamingAssets\data\simGameConstants with the file named: SimGameConstants.json you can edit the mission reward XP numbers so you can level all the pilots you took on a single mission to max if you wanted.
the problem with modding the game files is that you cant play multiplayer anymore if you do so. Using cosmos to edit your money in campaign doesnt change any game files, so it doesnt block you from playing multiplayer. I would much prefer to figure out a way to do it with cosmos