Just found Pre-Sequel offsets to fix commands acting as chat messages.
Credits to poorkingz for original Borderlands 2 tutorial:
https://www.reddit.com/r/Borderlands2/comments/42vs9v/developer_console_commands/
To make it works in TPS, follow the tutorial until you have to edit Engine.upk. Then change "Replace 1B E9 47 with 1B A5 14 in Engine.upk" with "Replace 1B 0A 49 with 1B A2 14 in Engine.upk".
Player Commands:
playerselectclass GD_Gladiator.Character.CharClass_Gladiator
playerselectclass GD_Enforcer.Character.CharClass_Enforcer
playerselectclass GD_Lawbringer.Character.CharClass_Lawbringer
playerselectclass GD_Prototype.Character.CharClass_Prototype
Note: Unlike BL2, only a few commands starting with "developer" works.
All maps names are in "BorderlandsPreSequel/WillowGame/CookedPCConsole" with "_P" at the end.