Ah, I think I've answered my own question! I've written out what's needed to the left of the grid, read along each line and ... confirmed my original hunch. Interesting how a misunderstanding of the rubric can lead to more trees than wood!
've just got started on this, my first Genius. I've got a problem with 24d and 26a. I think I've got them both, but the crossing letter isn't the same. Any help welcome!
I am happy with my solution to 22 across and believe the clue contains an extra letter.
I have spent days wracking my brain but still can’t spot it.
A nudge in the right direction would be appreciated, please.