Motorola already had MC88100+MC88200, a RISC CPU with pipelined FPU, which was many times faster than MC68030+MC68882. For floating-point computations it might have been at least 20 times faster than MC68030+MC68882.
NeXT had NuBus for expansion cards, so it would not have been any problem to have a NuBus accelerator card with MC88100+MC88200 and a decent amount of memory for that time, e.g. 16 MB or 32 MB.
MC88100 had been developed in parallel with MC68030. I remember very well the advertisements for MC88100 from 1988, because for some time it was the fastest monolithic CPU (until Intel launched the similar 80860 a year later, which had a higher clock frequency, because of being made with a newer CMOS fabrication process, the same which was used for the first 80486). The advertisements were that now you could have your own supercomputer by choosing MC88100, instead of paying millions for a Cray.
Wikipedia even says that Jobs wanted in the beginning to design NeXT with MC88100, but he switched to MC68030 due to price and availability problems, which should not have been a problem for the CIA.