The PO reported a long standing issue with the car suddenly quitting and today the car acted up missing/loss of power/and would have stalled without extra gas peddle. Then after maybe 2 minutes it cleared up and ran fine.

I drove three errands of maybe 3-4miles afterward and each leg the car ran fine.
The PO said it quit/ran ragged mostly when it was hot. This sounds like a fuel issue to me, but today was cool out 65F and it acted up before warming up..
Are there two issues here: Vapor lock and a separate fuel pump problem?

This same problem was last addressed by the PO at a garage in Boston about 6 weeks ago. The complaint: "Dies while driving"
The shop replaced vacuum hoses ($15) and "Idle speed motor (used)" ($125.00)
and changed the oil. $686.50 T (I got whiplash looking at this garage's bills) Did that guy mean Fuel Pressure regulator?
Looking at the 900 "Fuel FAQ" I wonder if the problem is in the gas tank
plumbing/ filter/ pre-pump? I can't tell if there's a pre-pump or not
and maybe have to call Volvo with my VIN # for this info?
It had a new fuel filter installed recently, and a bottle of injector cleaner
into a full tank today.

The fuel controller (mistakenly called a relay) is another prime suspect for funky fuel starvation. Usually they gag with heat and start working when they cool off. My failure started before the car warmed up and cleared up
afterwards? Are there different fuel controllers for Turbo and NA?
I have an old controller # 3523608 that might be right to swap in and see what happens ?

Am I on the right track thinking fuel on this issue?

Bill