Have been using the 18T with great success at small venues.
About to play a slightly larger one w pro sound reinforcement, but the guy relies on floor wedges, and we’ve gone all IEMs.
Will the multitrack streaming option allow live sends to his board?
I don’t know if this is the advice you are looking for but if the provider is a ‘Pro’ does he have an analog split?
if so, plug your mics into the split then xlr (or tails) from the split back to your 18T. That way he gets your mic’s/di’s for his FOH mix and you guys don’t have to deal with the wedges and you can stay IEM through your desk.
Hope that helps.
phatmat76 is exactly right, a splitter would allow you to run your monitors exactly as you have been doing. If no splitter is available, there is no reason a pro sound engineer would not be able to accommodate your IEMs. Most prefer that to wedges.