I have tried a Buildtak film for some days before giving up.
Sometimes the parts stick so hard to the platform that is almost impossible to remove the parts.
It is a platorm built to stick parts on it, and it does it very well, but by no means it is intended to regular printing. When I finish a print I presume I will be able to remove it from build platform!
If the part get glued to the Buildtak film, the only way to get the part away is by pure brute force. Then damaging the Buildtak film or not is a matter of luck.
Applying glue or hairspary to the bare glass is better than Buildtak, and cheaper.
IMHO, don’t waste your money on Buildtak!