I have tried to select several round handles in Spacing Note mode at the same time (avoiding clicking them one by one), but not success…
I though that selecting several square handles ant pressing TAB will made the trick, but it only selects the last of the round handles. If there is not another way to do that, it would be nice to apply the TAB feature in this situation.
Just a suggestion.
Unfortunately you cannot multi-select round handles yet.
(and I agree, multi-selection via shift click then tabbing would be nice.)