For anybody curious for where I think I can skip the additional constraint, I'm including an image that might show why I think I leave it out of the final puzzle.
The constraint, which indicates that the cell in c5r6 must be even, which forces a specific there. That forces a another digit in c4r3 and c6r9 (the three cells are tightly linked).
The image shows where the puzzle might be when your trying to deduce c5r6, c4r3, and c6r9. The center marked digits indicate what possible digits could belong there given light-to-moderate deduction. The corner digits are what would appear if c5r6 is a 7 (the only other possible value for that cell). I don't want to explicitly state my thinking for fear of spoiling anybody who wants to figure out how I put a digit in c5r6
I think the puzzle without the even digit constraint would likely be considered a point more difficult than I initially rated this puzzle.
If there is a problem in my assessment, please let me know.
The constraint, which indicates that the cell in c5r6 must be even, which forces a specific there. That forces a another digit in c4r3 and c6r9 (the three cells are tightly linked).
The image shows where the puzzle might be when your trying to deduce c5r6, c4r3, and c6r9. The center marked digits indicate what possible digits could belong there given light-to-moderate deduction. The corner digits are what would appear if c5r6 is a 7 (the only other possible value for that cell). I don't want to explicitly state my thinking for fear of spoiling anybody who wants to figure out how I put a digit in c5r6
I think the puzzle without the even digit constraint would likely be considered a point more difficult than I initially rated this puzzle.
If there is a problem in my assessment, please let me know.
