Converting the drive is only required when switching to a different drive model (crossflashing); now that you're using the drive as a 422 8, no conversion is required when using other 422 8 firmware.
It might have not been required in the first place, depending on how LiteOn did the EEPROM codes for the dvd1170, but that doesn't matter.
And correct, don't update the bootcode.
As for which CodeGuys firmware to use....that's up to you, based on how your drive performs.
From what I see, SCR2 (maybe the original SCR, as well) include some subtle use of Enhanced OHT by design -- the drive recalibrates from 1 time (8x burn with only one strategy shift) up to 4 times (16x burn with 4 strategy shifts). I assume 18x/20x/22x get 5/6/7 forced recalibrations (with a strategy change every 2x increase), and 6x & below don't benefit from SCR (one flat strategy used across the whole disc -- CLV writing). This is similar to the way LG DVDRW drives recalibrate at their shift points, though the C0deKing LiteOn implementation seems a little more intelligent & less likely to ruin a disc. :bigsmile:
Paired with the normal Online HyperTuning, the always-on SCR2 technique should replace the need for Enhanced OHT; the most critical recalibrations are forced.