Broken interaction beween multi-cursor and backspace-through-whitespace features

QtC seems to have gained a new feature by which a backspace though indention erases indentation-step many spaces with a single key-press, and not, as before, one space at a time.

Unfortunately, this behaviour is also active in multiple-cursor mode (Alt-↓/Alt-↑), breaking e.g. the following use-case: Open qsingleshottimer_p.h from qtbase/b6f962c87f5084eaf962bfb033b1398f80475120. I want to delete the inline keywords in front of the first bunch of function declarations:

I expect to need seven backspace key presses (no, Ctrl-Backspace isn't much better here), so I start with the first:

Oops, already out of sync. Each next screenshot is one more backspace key:

Getting critical now...

Boom.

Expected: the cursors stay aligned the whole time, so that after seven backspace key presses, I arrive at this state: