Prior to think of new interface you should consider replacing the outdated i7 computer with a new M1.
Looking your wishlist,
TB3 - Thunderbolt 3 connector (outdated)
Thunderbolt 3 w/ USB-C is outdated? Then I assume you would agree with me that Firewire and TB1, and TB2 (currently being sold by RME is WAY< WAY more outdated. However I found this: Thunderbolt 3 is capable of transmitting at a rate of 40 Gbps, which is a lot quicker than USB 3.1's rate of 10 Gbps or USB 3.0's limit of 5 Gbps. It's also double the bandwidth of Thunderbolt 2 (20 Gbps). https://www.laptopmag.com/articles/thunderbolt-3-guide
If TB3/USB-C is outdated, what connection protocol is available in Mac's that are currently available? USB4? Okay, I'll take USB 4 interface.
4in/12 out, 6in/16 out 24-32 channels. I don't need, nor do I want to pay for features/connectors I won't use like,word clock, S/PDIF, AES, etc. Not everyone has a giant studio filled with legacy gear. The vast majority of users are home recording enthusiasts who want quality pre's, AD/DA conversion, and rock solid drivers.
2 preamps - ok
2 Hi-Z inputs - ok
2-4 line inputs - ok
1-2 headphones - ok
up to here it is a Octamic XTC
4 line outs - 0k
MIDI I/O - ok
+DSP - ok this means Totalmix FX
Yes, I DEFINATELY want TotalMix FX. I LOVE the concept.
The ability to record a guitar dry/DI and later send that recording out of a 1/4in high impedance out, which can then be connected to pedal fx and amp, then recorded with a mic or through a load box/DI like my Two-Notes Captor X.
No doubt, it is a UFX+ !
It has all you want and it can connect every computer, including i7 vintage calculators.
Which costs $2800. That's why I said earlier, RME needs a product to bridge the gap between the Babyface - $949 - and the UFX+. The product that sits there now is the UC and UCX which are 10 years old with outdated Firewire and USB 2.
RME needs an updated interface in the $1500 range as a UA Apollo Twin X alternative. My suggestion is either an updated UCX or a cut down UFX+ The gap between Babyface and UFX+ is far too great.