I use two S-video inputs, and previously used 2 composite inputs.
Mixed them is possible, but not necessarly easy.
Each STB need to have it's own channel lineup (one with all the channels tuning S-VHS and other with all the channels tuning with Composite. If some channels are the same on both STBs, you need to Combine them in a single channel. Then MP keeps both tuning records (one for SVHS and other for Composite) but you see a single,"virtual", channel.
So the steps should be:
1 - Add all channels for SVHS STB.
2 - Add all channels for composite STB.
3 - Combine the channels that are the same.
Also note that the IR Blaster needs to handle different codes for each blasters. ServerBlaster doesn't support this. You need to check if IR Server suite supports.
Mixed them is possible, but not necessarly easy.
Each STB need to have it's own channel lineup (one with all the channels tuning S-VHS and other with all the channels tuning with Composite. If some channels are the same on both STBs, you need to Combine them in a single channel. Then MP keeps both tuning records (one for SVHS and other for Composite) but you see a single,"virtual", channel.
So the steps should be:
1 - Add all channels for SVHS STB.
2 - Add all channels for composite STB.
3 - Combine the channels that are the same.
Also note that the IR Blaster needs to handle different codes for each blasters. ServerBlaster doesn't support this. You need to check if IR Server suite supports.