You certainly may be right. I've got some replacement seals on the way to tryout, to see if that helps. If it does that would be great. All my seals have visually looked fine when inspecting them, but that may not mean anything if it turns out some of them are the wrong size or something else quirky like that.
I'm rather surprised none of your TC mods do SS. I would think most TC mods do SS nowadays, so I'm guessing your TC mods are maybe a little older?
Regardless, if you want to do SS TC you will obviously need to get a mod that can do that. Most newer TC capable devices can do SS, so you will have no problem finding a suitable device, and SS 316L wire is available from all suppliers. I'm not familiar with the other types of SS vape wire that are out there. SS 316L is the most common.
For the most part I like the iStick Pico 75W for TC. I like the design enough that I ended up buying a second one as a backup - and may even get a 3rd (the latest one with the multicolor resin finish). There are plenty other affordable options available as well. I'm eyeing a few myself, but I'm not really in the market for a newer design box mod right now.
Previously I had an IPV D2. I think that's the right name. I can barely remember anymore. It could do SS too, I think, but I only used its TC functionality with factory built TC heads. I found (at the time at least) that factory MTL TC heads just never seemed to work very well, but that was maybe about a year ago.
One of the reasons I got back into rebuilding was because I had read somewhere that was really the only way to get good MTL tank TC results. And, of course, I was sick and tired of buying cruddy factory coils that just never lasted me very long.
I don't think there is anything magical about a SS TC build compared to a regular Kanthal power mode build. For now, I just do a 3mm inner diameter, 6 wrap coil, using 26 gauge SS 316L wire. That's just a build I read posted by someone else here on ECF.
It took me awhile to realize (be convinced by other forum members I should say) that I didn't need to try building above 1 ohm coils to get good mouth-to-lung results with SS for TC like I normally would with Kanthal wire. Also, if you wick with cotton, unlike me playing with rayon wick, you should probably have an easier time than I did. Cotton is generally easier to wick with, and used with a proper TC setup you shouldn't need to worry about burning it.
I just got into using rayon early on for its better than cotton wicking abilities, to help prevent dry hits when using high VG juices in tight'ish draw MTL builds.
I am allergic to high doses of PG in my juice, so that has caused me a few issues in my vaping life. High VG juices don't run very well in old school CE4 type eGo era clearomizers. Back in those days, good high VG juices were hard to find as well. A lot has changed since then, but most factory MTL coils for MTL tanks (not that there are that many good ones anyway) still don't run high VG juices very well. So now I'm into MTL RTAs. There has been a learning curve to deal with, but I am now much better off for the effort.