But according to the OP, it should work like it does in AE – He describes doing exactly what I want it to do but for some reason, mine isn’t working.
I checked through the tutorials, which are old (working with CS4) and the only thing they said which I hadn’t done was to render to preview after applying twixtor – which I tried and it didn’t make any difference.
Also, it mentions in the tutorials that any advanced features of twixtor pro are used the same in both AE and Premiere.