Is there anything wrong with using the smaller hive to cap and "store" this first full super? I
your beekeeping cannot go that way. You must have some table or so where you stand.
Bees lift all the time rippen honey upwards and cap the honey. A small hive cannot do that.
When you add supers, you must put a new box between brood and super. So bees cap honey in good order and you can extract honey and you return empty combs then..
I understand very well the difficulty. My friend is not able to lift any full honey boxes.
She has no power enough in muscles.
I am 66 y and I have difficulties to handle full langstrot boxes especially to lift them topmost.
It is hard to backbone too.