will be installing a taco plate with temp sender on my next oil change.

I see the PET lists two gaskets for this application.

021 101 269A is a rubber o-ring for non sender plate

039 101 287 is a paper gasket. for the sender plate.

little copper seals are the same for both.

I remember using the rubber o-ring when installing the non-sender taco plate.

why is there a different gasket for the sender version?

Are they interchangeable?

You'll need both. It's been over a year since I did this on my old car, but IIRC there's one seal that's for the plate that holds the sender, and then one for the cover plate. I can't remember which is which, but it'll be obvious when you're putting them on.

You need both and the copper washers.
The paper gasket must be replaced, the others can be reused several times.
See my signature for the paper gasket templates.