In Sublime Text and Visual Studio Code it is possible to cut three lines with numbers, select lines with letters, do split to multiple lines, use Home to put cursor at line start, make paste and get this:
I just tried this out in Kate 24.08.3 - if I set up the lines as you have it at the beginning, turn on Block Selection Mode, select the numbers, then position the cursor at the very beginning (in front of the ‘a’), I get the result you’re looking for - perhaps a matter of not pre-selecting all three target lines before pasting?
Actually, that example could also be made to work in Kate by putting cursor before the numbers.
Those are just contrived simple examples to demonstrate how multiple cursors work with paste in other popular editors which have similar feature.
Block Selection Mode will not work with irregularly shaped text not at the beginning of the line or when selected lines are not continuous.
Sublime Text was one of the first (if not the first) editors with multiple cursors editing and it had a long time to perfect it. It implements special logic for pasting when there are multiple cursors on the same number of lines. Bonus is that user doesn’t need to think if Block Selection Mode needs to be used for some operations and how. Current conversation proves that point.
Sublime Text doesn’t have separate Block Selection Mode because such feature is simplest use case for multiple cursors and it is not needed. Kate had Block Selection Mode for a very long time before introducing multiple cursors like in Sublime Text, in my humble opinion it should follow that editor with its implementation of similar feature.
In Sublime Text this:
a a
bb bb
ccc ccc
1
2
3
Can be converted to this:
a1 1a
bb2 2bb
ccc3 3ccc
But cursor movement by a word from another recent topic is also needed:
Unless others have suggestions on plugins/other methods to address that particular use case, it sounds like what you’re looking for here would be a good candidate for a wishlist bug report for Kate so devs can assess?
But what if you want to paste lines from another application?
It is not ideal that you need to paste them in separate location in Kate, convert selection to multiple cursors, make copy and then paste at multiple cursors.
I strongly believe this is the logic, when pasting to multiple cursors Kate should check if number of lines in the clipboard is the same as multiple cursors and split those lines to corresponding cursor, i.e. each cursor should get single line from the clipboard.
With current implementation in Kate every cursor gets all the lines from the clipboard.