I’d be more tempted by a battery charger than the jump starting unit – even a pretty cheap one will tell you if the bike battery is fried and will top the voltage up in a controlled fashion.
An ocassional jump start off the car shouldn’t cause any major issues provided the battery isn’t too dead (if it tries to turn over it’s probably over 8V) just don’t leave the leads on for too long once the bike has started.
My biker mates disconnect the positive battery lead when their bikes are laid up for a while