How do I remove Drop Shadow (or other) filter after clicking Apply.

Is this an irreversible function? Can I look for a record where I can delete this feature after it is applied?

Go Filters->Remove Filters (last entry in the drop down menu).

Thanks.

Is it possible to remove individual filters?

https://graphicdesign.stackexchange.com/questions/166276/removing-an-effect-from-a-filter-in-inkscape