I understand exactly what I am doing.
I am pressing a now similarly named button in two calibre plugins that change the same calibre setting that is ordinarily accessed via this:
Which is stored in the calibre configurations, here:
If software was object oriented we wouldn't be having this exchange, because the 'button' in all three places would be instantiations of the same UI element operating on the same data item - but that holy grail of the 1970s has long flown the coop… coffee and pasta won the game
BR