We all have our own sensibilities about these kinds of things.so my rig look like this
Bass>tuner>preamp>HX stomp> Sushibox neptunium XLR> FOH
sushibox neptunium 1/4” out>radial JDI>flow 8>fzone p4>IEM
also, mic>mic splitter>flow 8> fzone p4> IEM
Ideally I’d run this all from my flight case pedal board.
You say that you want to move to IEMs for the benefit of your hearing and that your gigging situation is one where sound is always handled by the venues you play (and want there to be a limiter).
Maybe there's something I'm just not able to appreciate about your situation, but from my own experience, this seems like an unnecessarily convoluted solution and half-measure in search of a problem to solve.
It appears you're down this specific path because you sense that you'll want control of your vocal and bass levels in your mix, but not because you tried and found that it was a problem. Imagining myself in your position, and with the benefit of actually having gone through it, I'd hope to consider things more broadly starting with questions rather than answers.
Because you're already down the path, a first question would be, "Is there value in wresting just parts of my mix away from the sound person?" The same person who would be running your wedge is now running your ears. You can answer that question actually trying just a headphone amp. If you find that through sound check and potential adjustments, that having someone else controlling your mix doesn't work in actual practice, then the next questions are, "Why?" and, "Is just having control of my vocal and bass levels a solution?"
Does no one else in your band want to go to IEMs? What's the makeup of the group (number of vocals, instruments, e-drums?? ?)
Depending on your input needs, a fairly simple band mix (say, 3 vocal, 3 instruments, kick and snare), you could set up your own in-ear rig/split using a small mixer with enough channels to get by, like a Behringer XR12, Soundcraft Ui12 or a Mackie DL806 (discontinued but still around) and XLR y-cables (very well labeled) for not so much money, and you could fully control your mix.
That'd also offer the ability for others in your band to move to IEMs.