Good morning Alex and Micheal,
Indeed Alex, at idle, the capacitors inside the inverter are enough, then from idle to 75% load the ripple raises pending on all variable resistances etc in the DC line.
So, as you say, place for 75% load more capacitance (double the inverter capacitors), then for starting a load an extra same amount as the CLC we placed in the busbar or simply also directly to the inverters (a little less effect).
And/or, use the “formulae” as mentioned by me before.
Regards, Jeroen.