Flashable themes with secure boot (with PIN) hangs

I've recreated this problem with a number of themes on a couple of different ROMs so I'm hoping someone can help me find a workaround or a way for the theme providers to bypass this issue. I keep my HTC 10 encrypted using the normal means, and when I selected a PIN I enabled the secure boot option that requires a PIN. To be clear, if you are using this feature then when you reboot or cold boot after the initial boot animations it flashes up a screen that says "preparing settings" (or something like that) then you get an off-white screen with a prompt to input a PIN to decrypt. If you succeed, then it goes back to the boot animation and then it continues to boot to the initial login, which looks like your lock screen PIN entry and requires a PIN on first boot, even if you have fingerprint enabled. So secure boot has 2 PIN entry requirements., and it almost looks like 2 boots to get into a fully operational system.

Anyway, if I flash a zip them (say, one of the venom official themes, pureview, etc.) then it will get to that screen that says "preparing settings" and it will hang forever. It never allows me to input the decryption PIN so it can continue boot, and I have to reboot to recovery and restore. Can anyone help me address this?

Thanks!