Hi Daisame, thanks for your feedback and patience while waiting for this feature.
I'm happy to say that as of today, a device unlock setting is included with the 1Password for Android beta which includes the option for PIN unlock.
Before updating I'd like to note that we've found a regression which causes Biometric unlock to be reset when updating to beta 8.10.9-29. So, keep in mind if you're using Biometric unlock your password will be required after the update.
If you'd like to join the beta to try out this feature, you can find steps to do so in our guide: Use 1Password beta releases.
Let us know if you have any questions of if there's anything we can help with.