All of the above setups seem too complicated for this old man. Why not just eliminate the mixer entirely - you really don't need it.

With my rig, when I use a pair of L1 Compacts, I connect the right output of the keyboard to the L1 sitting on my right using a 10-foot heavy duty 1/4 inch unbalanced cable. Then I connect the left output of the keyboard to the Bose L1 compact on my left with another 10-foot heavy duty unbalanced cable.

My TC Helicon Harmony-M is connected to the keyboard's Line/mic input using a 6-inch 1/4-inch unbalanced cable. The TC has it's own effects, but you can also combine them with the keyboard's vocal effects if you need something additional.

All of the EQs can easily be set on the keyboard using the 5-band master EQ in the mixing console, and the 3-band mic EQ in the mic settings section of the keyboard.

If I have a guest or party host that needs to make an announcement, I plug my Samson Q7 into one of the Bose L1 mic inputs, which has a 2-band EQ system assigned to the mic input channel.

If I have a guest singer, which is extremely rare, I plug their mic into that channel and let them sing their heart out. If they want effects, then I tell them to buy a 6 channel Behringer or Alesis mixer with effects, and plug the output of that into the Bose L1 Compact's RCA connections, which works just fine for that purpose and without having any effect on the keyboard.

No mixer involved in my setup for a decade and I was glad to eliminate it from the rig.

Good luck,

Gary