Some thoughts on material…
PLA is probably the worst choice. I cannot think of any advantage to using it for what you want.
Resin will give you unparalleled accuracy. I suspect epoxy is a good choice for binding it to the stove. Which is also a risk. If it’s not quite right you will have to mechanically remove it (drill, file, chip). Resin has a rough / matte but uniform finish.
ABS will have visible layers / extrusion lines. That can be reduced using an acetone vapor bath.
ABS machines well. I’ve used files, wood scrapers, and knives to correct mistakes and smooth the surface.
ABS can be sculpted a bit. Wearing nitrile gloves dip a finger in acetone then rub the acetone on the part to soften it.
It can be “welded”. A dropper bottle filled with acetone plus some filament works a lot like a welder.
Acetone also works well to bond ABS to other things. Dip the part in acetone, shake off the excess, stick the part, wait a few seconds, then leave it alone.
If you use acetone with ABS, in my experience it takes about three days for for all the acetone to be released. Heat (e.g. leave it in the garage) speeds the process.
Printing pipe shapes can be tricky. The support material can make the bottom side a disaster. Especially for small parts. I’ve had fair luck not including any support. I’ve have good luck printing the part split in two then using acetone to bind the two halves together (that also works with PLA + epoxy).
My suggestion is to split the part then print the two halves in ABS. That should be an easy, simple, fast way to get started. If that’s a disaster then either try again with different print settings or move on to the resin printer.
I love talking about this stuff, pushing the limits of our 3D printers, and seeing your incredible work (!) so, if there’s anything I can do to help please let me know.