[Poudriere] Why does it install files without write access?

Hello!
Perhaps somebody knows how Poudriere works internally: I found that it coerces my port to install (during `make install`) scripts with permissions 0555. This breaks my post-installation hooks, where I am assuming that I can actually write to files installed into staging.
Why is it doing this? Is there any good reason behind that?
So far, it appears to have caused problems only on one build, but I may misinterpret the information on Freshports:
https://www.freshports.org/editors/sciteco/
Details and logs are in this Github ticket:
https://github.com/freebsd/poudriere/issues/1195
Best regards and merry chirstmas,
Robin