If you do mixing on the TX, be aware that the channel are turned down before the mixing happens, so if both sticks are down at 50%, it can mix back up to 100% depending on where the sticks are. I've seen plenty of motors blown based on the assumption that 50% travel adjust limits to half the voltage. If you're using SimonK you can probably adjust the settings to limit it to what you need, that way regardless of what your mixing is doing you can't go over the max.