Stove Pipe, Single Wall or Double, or Any Other Reccomend?

I should replace my stove pipe. Not because it's rotted, its just plain wrong.
Right now a 90 comes off the back of the stove, turned to like a 45ish angle, then a T is after that with a nonlevel, non plumb non secured barodamper hanging off there pointing toward the ceiling basically. Then another 90 goes into the wall. I have about 6 total feet of pipe.

The barodamper needs to be plumb and level, I could cut the T and try to plumb it up, but I'm wondering if an upgrade here with new pipe is worth it now.

I have no worries about nearby combustibles, the walls are stone, and I'm way more then 18" to ceiling joists to chimney entrance.

Should I go double wall anyway, will it be more efficient?

the present pipe is galvanized and in good shape, just shaped simply and badly.

Does it pay to use a T down low with a cap as a cleanout?

I am thinking doing this, straight pipe out of stove to 90, then a 45 to get straight again then a T with a plumb and level damper then a 90 into chimney connector. My option is a T down low with a cleanout, using double wall, and/or going stainless. I don't mind double wall if it saves coal and gets me better draft on warm spring rainy days.

I plan on running the stove 9 months a year for DHW and heat, and summer downtime for clenaing, improvements, tinkering. I'd run all year but the house is staying WAY cooler on the first floor with it off, due to the place just being downright old at 125 years now. prefer the coal DHW, but A/C vs turning it off is a weird tradeoff due to my situation.

I think most of us probalby just use the standard black chimney pipe inside the house as long as you have the right distance from combustibles.
It's cheap and usually last 3-5 years depending. Not sure if the double wall or equal would gain anything, other than keeping the pipe a bit warmer.
Sounds like yours is doing fine, maybe just replumb it correctly.