if im using a low/standard torque steering servo like around 40 oz-in of torque at 6.0 volts on my crt.5 on 3s lipo do you think it can overheat the esc/internal bec on the mamba max esc?
Yep. I ran a test a long time ago and found that even a low 0.25A load on the internal BEC (on 8 cells IIRC) caused it to heat up fast. Rule of thumb: use a switching BEC with ANYTHING over 2s or 7 NiMH cells.