Reading through the pages I am getting the impression that there might be some misunderstanding on how HYBRID/DYNAMIC CIEMs seal.
On Hyrbid CIEMs the bass driver is usually constructed with dynamic transducers. Dynamic transducer works best in a way when the air pressure is balanced inside/outside the CIEM shell. That's when a bassport comes into play. There are commonly 4 ways of adding a bassport.
1. Lazy route, drill a tiny hole and leave as it is.
2. Slightly more diligent way, cover the hole with fabric or lightly densed material.
3. Install acoustic damper, so higher pitched noised in more attenuated, also prevents dust from entering shell.
4. Install variable mechanism to control venting size, so you can play with the sound.
A fully vented shell and a fully closed shell may lead to up to 10db difference in the very low frequencies on the dynamic drivers. So usually a bassport is essential unless you are deliberately cutting down the bass. A vented CIEM will NEVER isolates as good as a fully closed CIEM since ambient noises will enter the shell through the vent.
AAW/ROOTH/UM should have employed the No.3 method on their hyrbids. So high pitch ambient is more muffled. However, vocal range, mrt noises, bus noises, most of them are low pitch sound. They should be reduced to a degree but it will NEVER be as good as how a fully closed CIEM isolates. ROOTH/UM bassport is on the faceplate and AAW put them on the top near the cable socket. Do not poke them open nor block them, you might end up unwanted change in the bass.
Above mentioned seal problems, some down right warrants a refit, some may just be the port playing the trick. Each should consult according to their own situations. Generally I would think you can achieve channel balance easily, you are good to go.
I hope the above helps