ok had another look. I just don't know how one can conjure the fileroller to drag something in it. fileroller only opens when it's doing stuff for you.
find nyxt on github, select targz:

at this point I don't know whose/what window this save window is ^^^? nemo's? system?
hit save. it closes. navigate via nemo-proper:

doubleclick and poof there is the fileroller:

at this point this is not some static window ^^ to drag and drop in, is it?
hit extract and fileroller morphs into another incarnation:

this window not active for drag and drop and never will be, right? ^^
hit extract a second time and mission accomplished:

so, like Axios, I spoke in error as well. I thought you meant some variation of all that stuff I posted.