It’s probably been 3-4 years now that Temflex has been my go-to grafting material to supply the structural strength in the graft. I’ve also used the generic version- it is just a self-sticking, but non-adhesive rubber electrical tape.
I often see it hanging around a year later, but it starts to break up and fall off by that point. So even if it hangs on for another year or two, it isn’t a serious impediment to growth. In fact, I prefer that it does, as it helps me find the grafts. Sometimes unions heal enough that I have trouble picking them out and tags have a habit of falling off…
Unlike the green vinyl (not sticky) tape which I used to use to tie grafts shut. I tend to do a lot of grafts (just under 2000 in the last 8 years, per my spreadsheet), so I often forget to do follow-up on each one. I found a few vinyl ones ~2 years later and they were badly disfigured.
For me, the Temflex is on the bottom. I do like to pre-wrap the scion with parafilm. This winter I even pre-wrapped some when I first received it, rather than on grafting day. But I don’t cover the bottom end of the scion (the part where the union occurs) with parafilm until I’ve connected everything with the Temflex. At the very end, I wrap the parafilm around the Temflex. I’m not sure it is necessary, but I figured that it would make for a better seal and would also cut down on the temperature swings on sunny days by shading the black Temflex from the sun a bit.