1U rack mixers are always a bit hard to find, but the 1602 V2 is cheap, readily available and absolutely worth the effort if you're simply connecting a mixing a lot of electronic instruments. It's not the cheapest Behringer mixer but in terms of cost-per-channel, it's cheaper than an MX400 micro-mixer!
I'm so impressed with the low noise and simple gain and panning controls that don't move too easily, the easy-to-read level meter and the switchable levels per channel that I've seriously considered just getting two more and using them as sub groups to an Apollo 8 - that would be 48 channels, or 24 stereo synthesiers and sound modules, all individually adjustable for gain when there's an irritating low or high level of patch, and with simple muting to get rid of the USB-beep-and-chirp troublemakers.
It feels solid and well made, has a proper IEC socket for power so no wall-warts (unlike many cheaper desktop mixers) and the headphone output can be switched to use as a monitor/FX send. I find the headphone output handy when creating patches as I can listen to the layered synths before they're in the DAW.
It's very hard to see why any electronic music producer would need anything more sophisticated, if they're doing all the channel strips, EQ and effects 'in the box'. If I make it to summer 2025 without buying more I'll be amazed.