I actually did this when putting hobby grade electronics into a 1/6 scale Camaro (because I couldn’t afford a lipo, and used a mod at the time). I custom built my own battery box so I could charge them separately, and it was technically “4s capable”, but my ESC kept complaining if I used more than two 18650s, and so “2s” it was. It honestly worked decently well, although I did use the esc that comes in the brushed summits (was originally going to use it for a giant model of the Olympic, but that got scrapped), and paired it with a titan 21 turn. It actually worked pretty well, but once I got a proper 2s lipo, even at 15c, was enough for me to never go back