Well.. my other large concern is SD card logging which plainly does not work well. If we turn back the clock 3-4 years then maybe it sort of worked ok. With recent firmwares it's just a mess and not cut out for racing (or advanced use).
It seems worse for situations where you turn the ECU on/off at any point, but worked well in the past so recent firmwares seems to have a bad way of dealing with this.
I also have serious problems reading the card over serial port at any speed (timeout) while it works great in a SD card reader plugged into the PC.
Do note, this is based on testing on several ECUs, but in particular I have an ECU that works well with SD card logging with older firmware (pre 1.1.9x) and not so well at all with recent (1.2.x+, tried many as well as the latest 1.2.23). The only way to get a proper log on the SD card is to turn on the ECU, start logging to SD card _manually, start the engine and do whatever, stop the engine, stop the SD card logging manually, remove card and put in SD card reader - voila!
Maybe the type/model/make of card is very important, but it should not be unless there is a problem conforming to a standard (card vs firmware).
The whole point is to datalog the GPS speed to get live propeller slip data in a boat.