It has a high chance that it will work and there is nothing stopping you if you would like to try it
& Why it is necessary to flash dm-verity file after flashing rom why we do that other wise phone go into bootloop could you demonstrate?
/* Your warranty is now void. * * I am not responsible for bricked devices, dead SD cards, * thermonuclear war, or you getting fired because the alarm app failed. Please * do some research if you have any concerns about features included in this ROM * before flashing it! YOU are choosing to make these modifications, and if * you point the finger at me for messing up your device, I will laugh at you. */
Derp is dead, dev deleted the source. The eureka team said that only some roms would be coming out on this month. Ancient is dead for a20 probably so the only official 12.1 rom we have for a20 is Spark OS