Since models like RMC's prototype I-bar coaster is already in the game, I am hoping that the following models are added as well since these are literally all over the planet compared to something like RMC's prototype that is real, but not built anywhere yet.
Hopefully the following examples become possible before final release:
This coaster (Superman at Six Flags discovery kingdom premier launch) is already in alpha 3 , but we can't choose how many forward/backward launch cycles to run as well as alternating/increasing speed/acceleration per cycle.
Wicked Twister at Cedar Point...This coaster type was in RCT2 and 3, hope it makes it to Planet Coaster, where we can control cycles and their corresponding acceleration/velocity parameters.
Vekoma Shuttle - (Goliath at Six Flags New England)
Boomerang- Hoping this functionality (reverse incline) gets added because this model is literally all around the planet!
Superman ultimate escape - this inverted shuttle launch model had a holding brake on one end.
Hopefully the following examples become possible before final release:




