Dont know why i didnt think of this earlier but you could always get a hob overflow and a new pump to address the the flow issues.
Im not a huge fan of them but i do have an eshopps overflow on a 150 gal. Its a little noisy and not as flood proof as other methods but better than nothing
JK47 what ya think ?
Drop a black sponge in the last compartment and a fitler wool on the sponge.
the noise issue is gone. Everyday just rinse the wool.
Thats what i did for my overflow box which is like the CPRs







