Currently not much has changed, just drove it some over the weekend to see if the new fluid and additive could work some magic.
The one new thing I noticed is that I can get it to shift pretty quick by just going from D to 2 a few times, very gently, not revving the engine to much and just lightly giving it gas and taking off. Then it shifts normally after that first forced shift.
I also noticed that the car kind of rattles under acceleration during this period of warm up. Checked all the exhaust covers,etc.. to the best of my ability. This rattle goes away after car is warm. The car is running really nice overall and is really fun to drive.
So it's hard to tell if things have gotten better or I have just learned how to work around this issue better. The good news is I can teach my son this hack and it seems safe enough for him to just do this around the neighborhood before driving to school in the morning.

Yeah, I think if I drop the pan I may go with cutting the dipstick tube, that approach looks pretty easy.

The local independent Volvo mechanic recommended a transmission shop, I called and they can do a free diagnostic check. I talked to the guy on the phone and they seemed pretty trustworthy and down to earth. I may go that route after another week and just see what they have to say.