The 4 Hard-Stiff/Soft (DIG/ARC Force/Arc Control) settings are going to provide additional amperage when the load voltage drops below 19 volts. A short (root pass) tight arc length with XX10 electrodes could have the possibility of the arc short circuiting/going out.
You have five settings for XX10 and five settings for XX18. Even though it shows 2 for each. There is no law or code that says you have to use XX10 settings for XX10. You can use XX18 settings for XX10 if you like that arc characteristic. Or, you could choose to use none (DIG/Arc Force-Additional Amperage) by setting it for Lift Arc TIG.
For XX10 electrode, Set the desired amperage with AMP ADJUST control and the PROCESS SELECT switch at Lift Arc TIG, weld; identify the arc characteristic. Leaving the AMP ADJUST amperage set and only change the PROCESS SELECT; Change to XX18 soft, identify the arc characteristic, than set XX18 STIFF, identify the arc characteristic, than set XX10 soft, identify the arc characteristic and then set XX10 stiff, identify the arc characteristic.
Repeat the above exercise with XX18 electrodes.
Take a really deep breath & Then set the PROCESS SELECT to the position that you like for the electrode type & can weld and qualify.
Amperage is penetration, additional amperage is additional penetration and at a really short arc (low voltage) length it is nice to have the additional amperage for the additional penetration to prevent SMAW short circuiting/arc outs.