Bit of head scratching but doable.
Yes. I think the offset base has a lot of potential, but it is supplied from the manufacturer as a bit of a half trick pony.
You can mount the plastic bit onto the standard base casting and install a handle in the hole for the offset part. It gives you a nice wide base for stability.
I suspect these are end of line stock clearance prices, so they are worth buying to put away for the future.
I have drawn and 3D modelled the plastic base bit, so if it is any use, I can put a copy here. Can you show a picture of the bush you want to fit (Trend style or Porter Cable style?) and I can 'virtually' see what possibilities there are.
If it is only a single size bush you need, a bespoke 3D printed one, that is unique to the base, might do instead of one following existing size/design conventions.