Spaceflight

Boosters would have to be carried, which is bringing extra weight into space. It also means Astroscale would need to be periodically resupplied with more disposable boosters, or just become a piece of space junk itself.

Nudging is way more efficient. You could calculate the trajectory needed to nudge a piece of space debris into an unstable orbit while keeping your own orbit stable. Or, a simpler method, just keep some extra fuel on the Astroscale to make minor adjustments to orbit as needed after capture.