This one did not take for me. I had updated WhateverGreen (1.3.8), Lilu (1.4.3), and Clover to 5109. Upon the initial reboot the disk options for the update were missing. I noted posts earlier in the forum that said to do the F11 thing to clear NV Ram. That got the options to appear, but when selecting one of them the system boots to the apple logo/progress bar screen for a brief second and then reboots. Once it booted to the "Installing" screen and said 20 minutes remained. That's about what it took on my Macbook Air. About 1 minute later it crashed and rebooted.
I noted an earlier post that Clover 5109 had issues so I downgraded to 5108. Consistently the upgrade options reboot almost immediately. I suspect there is something making it unhappy but am not sure what so will wait a few days and see if perhaps there is a newer Clover release that might make this work. At least it remains possible to get back into the previous 10.15.4 by selecting the appropriate option at boot time.