agreed with everyone else, the planned environment is plain stupid, total disrespect to the real power of the drugs. Enjoy the rollercoaster for what it is, maybe a little bit of MXE would make it a little more fun, but keep the DMT to a controlled environment.
As for combining MXE + DMT (minus the rollercoater, just please get that idea out of your head), I've had nothing but positive but also VERY POWERFUL experiences with it. Only take if you are experienced and very comfortable with both drugs by themselves.
I once vaped MXE + DMT at the same time sandwiched between some cannabis, wow what a blast off!