Multi-version/Bedrock support
Nothing here was tested yet. But it should work fine.
Multi-version support (ViaVersion):
By default Spectrum Survival supports only one version of Minecraft just like Vanilla servers. You can change it by using ViaVersion (either as a standalone proxy (ViaProxy) or on Velocity).
Bedrock support (GeyserMC):
Spectrum Survival is a Java Edition only server. But by using GeyserMC (either standalone, Geyser-ViaProxy, or on Velocity)