The Hudson HuC6280 of PC-Engine fame is a chip very similar to the SCC. It has six 5-bit waveforms of 32 bytes each. Two channels can be combined for frequency modulation and white noise. The SCC(+) has four (five) 8-bit waveforms of 32 bytes each.
So two SCCs combined with the PSG should probably be able to emulate the HuC6280, with the exception of the frequency modulation feature (let’s hope it’s not frequently used).
Chris Covell made a music disk playing SCC music on the HuC6280. See the links in that video for more details.