Microsoft has a handy overview page of all Visio shortcuts:
https://support.microsoft.com/en-us/office/keyboard-shortcuts-for-visio-ee952f31-7e3e-4564-8116-f3ecbb733cc1
Needed it to decide under which keyboard shortcuts to put various macros, to avoid shortcuts already assigned to something really handy.
I think most part of keyboard combos assigned and you can't find unassigned combination with Ctrl, Shift and some letter :(
Yes I found that too, need to use CTRL + SHIFT + LETTER combinations not ideal.
I prepare this table (https://1drv.ms/x/s!AtkXDoV-JdfIgZdM4CDmiY42tw2VuQ?e=0zWkxX) from your article, you can filtered and sort items in second column for find unused Ctrl-related combinations.
Thank you Surrogate very handy!