Vortex Sound Research

I have a Juno 106 (fully restored recently) and a Prophet 6. I'm using a UAD Apollo X4 for my interface but I use inputs 1+2 for guitars/mic. I like going direct from synth to Apollo and never really got into using a mixer but I do want to have both Juno+Prophet setup to record, at any time, without choosing 1 or the other.

I could get a mixer and just run stereo out to Apollo 3+4 but I hate to add another layer inputs/outputs and gain staging etc.

What are some suggestions for this setup to always be on? Mixer advice or suggestions? Trying to simplify the studio but have everything ready to go at any time (play/record).

Thanks!