The other variables I mentioned as just totals I wanted to convey - not actual slicer variables as far as I know.
Re your ‘Variables used to estimate filament usage’ section.
I don’t think the flush total that you are presented with in the slicer includes the total volume of the prime tower - that seems to come in the model total for some strange reason.
Fairly easy to confirm this by just changing the prime length and reslicing - you will see the model total change but not the flush total.
In terms of your test objects I guess it just depends on whether they include a prime tower in the 3mf and calculations.
Not really sure why the prime length is split into 4 fields - I know in Prusaslicer you have view flushing volumes either as totals or separate unload/load values - so I wonder if the 4 fields somehow reflect this - might try testing it out one day.