sorry for my late answer. (Had some free days)
You were absolutely correct.
After downloading the package again and extracting it to the 32bit mod folder everything works smooth in the "RemoteSigned" Policy.
But i've also tried the install.ps1 script. Which seems to work just in the mode it is started (32bit ISE for 32bit folder and 64bit ISE for 64bit folder).
Would be cool to have one handling both if running under 64bit.
-> Also it extracted the files to the 64bit folder but not to the 32bit one. It just deleted the old version there but no new were shown up.