How do I keep wrinkles out of tubeless rim tape?
I don't know why it's so stiff, but other brands of tubeless tape are also stiff.  Many riders do choose to use Gorilla tape.
If the wrinkle only creates a small air bubble, but is sealed at both edges of the tape you are probably ok.  If the wrinkle reaches the edge of the tape, i'd redo it.  I found keeping the tape taught, but not with too much tension, and coming behind and really pressing it onto the rim an inch at a time works well for me.
It really depends what the problem is.  I've had tubeless setups seal immediately, i've had one that took a full week of the 'shake and turn' technique and i've had one that did indeed finally seal after 2 weeks of riding.


If you are losing pressure that quickly (4psi in a few mins) there is definitely something wrong with your setup - generally even without any sealant the losses are in the region of 0.5-1psi/hour if things are setup right.
Take the wheel and either stand it upright in the bath and slowly rotate to find leaks (don't dunk the hub!), or liberally coat it in soapy water and look for bubbles