Oh it can actually! through using E0x. You store a configuration, like ">//7F00000000000000430" in a instrument name, and then through using E03 in any effects column you initialize echo with that setting. You can change between up to 12 settings at the same time through E03 - E0F where E04 uses next appearing and futher. The configuration is not documented to the disappointment, but the SNES vst C700 has an inbuilt echo calculator for xmsnes that came in handy when I finished my .spc entry :D