As for modding, I have not tried any mods nor any custom maps, though the custom maps I'm sure are very interesting. It would seem to me those options are much easier and retain the same excitement, than having to get a trainer. This will allow you to keep all your map knowledge, all your blueprints, all your stored weapons, all your skills, from a previous play-thru. In addition, on a second play-thru you can always choose New Game + Mode. So what is the point of having a trainer, given that you can find these Easter Egg weapons simply by watching YouTube and doing what is necessary? So you can have an unlimited supply, just requiring common scavenged ingredients, of the EXPcaliber and the Korek Machete, if you require that. The copies are nearly as good as the originals.

The same is also true for the Korek Machete, which also provides blueprint for copies. (There may be one mode, either Hard or Nightmare where you cannot use one of these Easter Egg weapons, per the Wikia it is Nightmare mode, but you can use EXPcaliber) In-game without trainers, the EXPcaliber can be found as an easter egg. EXPcaliber, Korek Machete, New Game +, may be simpler solutions to a trainer.

Dying light cheat engine 2019