Question Author
Well done geevo, you get the gong.
After the unsuitable 7-letter possibilites a,re eliminated, just three remain. Two of these end with the same four letters, 2, 5, 21, & 14, leaving 3, 16, 23 at the beginning of one and 25, 23, 26 for the other. If 23 is P, the only two possibilities for the other word, --pical begin with a T. The initial letter for that possibility is 3, which can't be T as T then must be 23. Hence we get 'Optical' in the vertical position and 'ethical' in the horizontal position, both sharing th corner L.
A bit convoluted, I know, but it's like that sometimes.
As for NACW's point, I think that s/he's right but we seem to have to allow a lot of 'poetic' licence to these setters. Incidentally, by a complete coincidence, I discovered that yesterday's Ultra Alphapuzzle (no clue given) was identical in all respects to the one published on May 15th, 2020. Now that's cutting corners, in my book!