Gaskets in general with very few exceptions unless they are for a head or high-pressure sealing are not really a concern as long as they are cut correctly. I couldn't say who the actaull manufacture was of the gaskit it came in a transmission filter and gasket set.
Basically, every just about every gasket failure I have seen and read since the 70's was directly caused from the user. Naturally there are a few exceptions that were how engine were manufactured and many of those issues were later corrected with changes made to the parts.
To make this point as well for other consideration of observations I powder coated my transmission pan bright white.

 

Makes sense to me; there’s just so much variation in applying the RTV properly. Not to mention the possibility of allowing some to get into the pan and mixing with the trans fluid. Rubber gasket seems like the safest and most repeatable option for future pan drops.

I have read people noting that factory torque spec with the rubber gasket is not a good idea because that spec was meant for the RTV and not the thicker profile of the gasket. The gasket deforms too much at factory spec. Did you tighten to just under factory torque spec for those pan bolts?

And how long has it been leak free (since your last pan drop)?

 

I drop the pan to replace the filter at 10 k intervals.
The distortion of a gasket is from inexperience torquing gaskets in general. Your thoughts about sealer only in one sense applies as well.
Fo me personally I see what the torque specification is and any notes. If I use a gasket which btw seldom ever 100% rubber and then when I start getting close to the FSM torque values, I start adjusting my final torque number to how the gasket is compressing. I almost never get a gasket that leak based on this method. I also re-check the pan bolts after a day or about 50-75 miles before reinstalling the plastic undercover.

This may help with some questions about my general servicing also most all my oil analysis results over the years?
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Wow every 10k miles! Wish I could go back and at least do that after the first 20k miles of this vehicle's life but c'est la vie. So you've used the rubber gasket (could be mix of EPDM, natural rubber, etc.) every 10k miles? Never had a problem with leaking? Any recommendations on prepping besides make sure surface is free of any previous RTV and is degreased? In the past on my other vehicles I've had problems with trans fluid wanting to drip down to the lowest point on the mating surface even a couple hours after dropping the pan. I would wipe but the fluid would replace itself almost immediately (I use ramps for a job like this so there is a considerable low point in that scenario).

 

I said I do not use rubber gaskets and avoid them at all costs unless that is the only type available like for timing chain covers. I use Felcoid gasket's.
I will set aside a few hours to do the pan/filter service. I let the engine and transmission warm or as soon as I return from a drive remove the drain plug and let the oil drain for as long as I can. The same with removing the pan letting the oil drip to the point a drop about every 2-4 minutes apart before attempting to replace the pan. This is so as not to contaminate my clean surface for the new pan gasket and re-installing the pan.
I also recommend that you look at my thread. Most of your questions can be answered alone with dozens of photos.
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