I thought I recalled seeing some n00b saying a while back Furnace could be used for PC-x801, but it's not mentioned on the Lyceum page. am I misremembering or did it change? maybe they were assuming someone had already made a .vgm to .s98 convertor, or perhaps that Furnace had .s98 export?

(totes not just asking because I can hardware render ym2608 .vgms on my MegaGRRL)

to my knowledge no it cannot because it only exports to vgm and you need s98 (or the mml options). you could use it for the vgm format

https://github.com/digital-sound-antiques/s98-to-vgm
I don't know if there are any limitations