Booting to Recovery Mode won't work anymore
On Dosdudes's website, they make a note that if you use APFS, you will not have a bootable Recovery partition:


Select the disk or partition you want to install on, and erase it, ensuring to use either Mac OS Extended (Journaled), or APFS as the filesystem type. If formatting an entire drive, ensure GUID is selected.
-- Please note that if you use APFS, you will not have a bootable Recovery partition.


Emphasis mine
Granted, the install document is from the &quot;High Sierra&quot; page, but APFS implementation between High Sierra and Catalina isn't so different that Recovery will work in one and not the other.
As for your graphics card, I highly suggest flashing (IMO, this should have been done prior to installing your Catalina patch so you could diagnose issue if/when they arose).  See this answer for some links on how to do this procedure.
If you need a Recovery Partition, try Internet Recovery or boot from a USB installer.