I have many wireless microphones but, I love to use my SHURE Super 55 Retro Microphone to gig in parties or events because it looks great and I love their sound, but... you know... it is wired.
Then, I though to convert this mic in a wireless mic using the adapter XVive Audio U3 XLR, so, when I used this configuration with my Bose S1 Pro, connecting: Transmitter in Super 55 and Receiver in S1 Pro... That works lovely.
Now, You know, the XVive have their own power supplied by a rechargeable battery in both, (transmitter and receiver) so, when I was tried to used with my L1 II through the ToneMach, this start to bring sporadic "booms" in the speaker. You know, like an overcharge or something like that.
Then... Can I connect "safetly" an XVive Audio U3 XLR (Microphone or Guitar) Wireless System to ToneMatch Mixers?
If you're asking if your wireless mic system and/or a wireless guitar system can connect to a Bose T4S or T8S mixer and then to your L1 Model II, then the answer is yes. The Xvive U3 simulates a wired connection so the mixer or PA doesn't know that it's a wireless system connected to it. I can understand it working fine with your S1 Pro but I'm not sure how you connected the Xvive U3 directly to the L1 -- you said the ToneMatch port? There's a line-level analog input in the L1 power stand that accepts a 1/4" TRS cable but that's about it.
One note about the Xvive U3 -- as you probably know, its based on the 2.4GHz wireless spectrum, which is an open ISM band used by bluetooth, WiFi, microwave ovens, among other things. If there's any interference from one of these, you may need to change to a different channel for your system or remove the source of the interference. Outside of that you should be good to go with a Bose T4S/T8S mixer and your L1. I run a Shure wireless guitar system through mine with no issues whatsoever.