pretty much what i use, tho i use the hex on the outside of the pot and seal inside with an elbow to point down.
If u go SS then hop onto ebay and get some M20 (20mm id) SS Washers,
u may need to file a wee bit out the centre to get em to slip upto the hex on the nipple, but an m21 washer would have gaps thru by the straight edge of the hex.
a 1/2" bsp locknut could also be helpful allowing you to fit and seal the nipple and then just screw on the valve..
Also in conjunction to ptfe tape a sheet of silicone baking sheet or a £shop set of flat bottomed silicone moulds for cutting your own soft diy washers, and the last resort seal solution feronox lsx silicone thread sealer, when cured is suitable for potable water.. and just a dab on the thread will help seal.
inside
outside
a temp fixing i used for chiller testing but shows the hex and washer and silicone diy washer in use.
Also lining up things is a bit tricky with SS as unlike softer metals u cant just apply a bit of oomph and turn it that extra bit.. SO test screw and count the turns needed to lock the bits together, then wrap with ptfe to fit (use a load), and count to one less turn and line up, if you over turn, start again as a back twist will possibly allow a leak. (thats where the silicone thread sealer cam come up trumps..)