First clover boot stage horribly slow after 10.12.6 update

Today I updated to 10.12.6, and now suddenly the first boot stage where it goes

OsxAptioFixDrv: Starting overrides for System\Library\CoreServices\boot.efi Using reloc block: no, hibernate wake: no 

takes forever until it comes to the +++++++++++++++++++++ part. From there on boot time is the usual 10 to 15 seconds until login screen.

Usually that first part used to take like 5 secs now it literally takes 2 minutes 30 seconds.

It didn't happen instantly, first I installed the 10.12.6 combo update, then I rebooted the first time, installed the new nvidia web driver, rebooted again, then tried everything out and rebooted again for no specific reason and only then started it taking 150 seconds, the first two boots after the update still were normal.

Now every single boot takes this long though ...

Anyone know how to fix that?

Edit: I already tried the newest Clover version on a USB stick with a clean config and it had the exact same issue