Hey bud,
I really hope you can keep Phyllis and enjoy the retic experience. I talked to a very experienced retic buddy and he says some just push and there isn't much you can do.
I ended up being lucky, at least so far with Wallace. I certainly would not keep more than one of these. I love having him, but I'm like you are. I enjoy the relaxation and easy handling of my boa and coastal carpet.
If Wallace handled a bit better I'd be thrilled.
He produces minimal waste. He's like the carpet though he eats more frequently, not a lot more often but a little bit.
His size is still increasing but most of it is girth. I could deal with another foot, but really don't want and never did want a true giant.
As of now the cage is perfect, he is just the right size. A much larger animal would really limit what I could do with my setups.
Keep Philly if you can, and look at a nice, Brisbane locality coastal to fill the other cage.