Yes, make sure to comment out the G29 G-code and put the M420 S in after G28.

From the Marlin documentation you can read:

Get and/or set bed leveling state. For mesh-based leveling systems use Z parameter to set the Z Fade Height.

With AUTO_BED_LEVELING_UBL you can use L to load a mesh from EEPROM.

Also note that

• G28 disables bed leveling. Follow with M420 S to turn leveling on, or use RESTORE_LEVELING_AFTER_G28 to automatically keep leveling on after G28.
• The “current position” may change in response to M420 Sn.

Yes you can disable the bed leveling procedure, just make sure to comment out the G29 G-code and put the M420 S in after G28 in your start G-code.

From the Marlin documentation you can read:

Get and/or set bed leveling state. For mesh-based leveling systems use Z parameter to set the Z Fade Height.

With AUTO_BED_LEVELING_UBL you can use L to load a mesh from EEPROM. Option L followed by an integer (M420 L<int>) -> Load mesh from EEPROM index (Requires AUTO_BED_LEVELING_UBL and EEPROM_SETTINGS defined in firmware)

Also note that

• G28 disables bed leveling. Follow with M420 S to turn leveling on, or use RESTORE_LEVELING_AFTER_G28 to automatically keep leveling on after G28.

This implies that if RESTORE_LEVELING_AFTER_G28 is set in your firmware, you do not need the M420 S command.

You can test this by removing G29 in a current print, if you don't see the Z stepper move during the first layer, the RESTORE_LEVELING_AFTER_G28 is not defined in firmware and you will need to use the M420 S command in your start G-code directly after G28.