OK, there is a shortcut I forgot.
I saw it in the manual but as a new user I do not remember it all at once:
One can select a region and then respell all Db to C# of course. I will create a new habit now.
And separating by commas results in just one shift-i popover command.
I feel so good I found the cure for most of the trouble myself. Reading the manual helps, the necessary section might come to you suddenly from the back of your head.
But still: stick to pedaling shorcut for Harp would be cool.
I understand also that this is not a priority.