I found yet another variant today which might be interesting:
https://crisslecrossle.com/
Although I wasn't sure I fully understood it, my first attempt was pretty successful. It seemed to make life easier than I was expecting.
Crissle Crossle 451 3/8
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crisslecrossle.com
#crisslecrossle
I must have a go at Fibble again - that was insane.