Part of the problem is assigning what power belongs to
the inverter, to the load and to the source. This wants
to fit whatever power estimation tool inputs need to be.
You have three terms as far as current - input charge
(which includes Miller kickback), shoot-through charge
in the supply-supply path, and load charge. If it were
me I'd characterize them each separately and then
combine if somebody wants a simple answer (but keep
your tool / analysis options open for later, when this
info has to be made useful for design or whatever).