I was fairly happy with the endgame until I came here and saw reference to a "letter count" (of 19 or 20) - I can't work out what posters mean by that; it doesn't seem to relate to anything that I've entered!
The across message seemed fairly straightforward, apart from an unexpected aspect of the fifth which nevertheless has to be done to get a sensible instruction. The final two words from down clues also seem self-explanatory (it's just all written weirdly).
But the first two words are giving me pause, because the work I have to do to get from them to the thematic phrase seems a bit half-arsed (if you see what I mean). My thematic phrase is two words, and one required no imagination, and that's making me wonder if I should be thinking of something cleverer!
(The puzzle has been a lot of fun though! Symmetry very helpful, as were coloured pencils.)