Hi John,
You may want to run some retraction tests - I’ll share a link to a useful trick.
With PETG consider starting the test with a retraction speed of 40 mm/s and a deretraction speed of 20 mm/s then tune speed as needed.
Z-hop can also string some petg filaments you can put a zero to see and then fine tune the Z setting.
The length can be as short as 0.4 or greater.
Maybe this will help you out with your filament 