My build has flight safe batteries.
You just have to combine two to use in the board and swap them out with the other two when they run flat.
The wiring harness is pretty straightforward if you understand how BMS’s are wired but they still take up some space. It’s a compromise I had to make for this board. I currently have three, all DIY.
For such a wide range of requirements, there is no “one size fits all” for eskates. You either make compromises or have multiple boards for most of your use cases.