Anyone using Marlin Firmware. I've had good prints with the LIN_Advance enabled.

Thanks. I’ve still got some tuning work to do, but as soon as it’s dialed-in I’ll give it a shot.

Did you enable ADVANCE and LIN_ADVANCE or just LIN_ADVANCE?

Don’t enable ADVANCE.
Only enable LIN_ADVANCE in the advanced configuration file.
You will need to set a K Value.

If you’re using a Bowden, try starting with 300.
If you’re using a direct drive, start with 75.

You will need to increase/decrease until you feel the print is perfect.