Werd, Now the wheels are spinning even faster I see. That could forking work man.
Because of the diameter being very small and the ability to cut to length you may get away with it staying cold enough under (proper/ meaning in my eyes over insulated)insulation although the same premise applies and it will try to reach room temp, the biggest thing overall is the shank base and tap head will always rest at room temp. The only real issue I see is getting the S/S line mounted and permanent into the coldbox without some super engineering (maybe flare the end inside a flange to keep it in place inside the cooler?) I do recommend looking at building a simple trunk also just to see all the options on the table before committing to one
Don’t get me wrong sometimes the hunt and the commitment/ tinkering/ engineering alone are the fun of stuff like this. But you asked for comments so I gave the one/s I think will serve you best in the long run. In this situation a trunk line will always work best as it is mounted out of the way you are not reaching or grasping for disconnects/ line every time you change out a keg or other also think long term ergonomics too key words here are Long term, No hassle, Maintenance free, otherwise if it is always a pain to change a keg out or get into the chest or clean lines or other misc… you will be back to the coldbox outside the wall in no time.
Edit* I spoke too soon. The line and shank are both chrome plated brass?, I think, I dont know if they braze S/S line to a chrome plated brass shank here or what. Its not a huge deal either way but S/S will last a lifetime and beer being acidic will eat away at the chrome overtime exposing the brass. I’m sure this is all known I just will not be the one advertising S/S unless I know it is for a fact.
satisfaction might be of interest to you.