Programmability is nice, but in theory you can put the soft start and stop functionality in the receiver, if you program it yourself (arduino). You will need something to save the gearbox, if it is the ESC or the receiver/remote doesn’t matter much.
But as Alexandre mentioned, you will probably run into trouble with a 6s setup. Much higher currents that will flow and put strain on the ESC and wiring. Especially the ESC won’t last long, those hobby ESCs aren’t meant for that kind of abuse, they are designed for really short bursts not human transportation with long periods of high current. When it says 150A continuous that doesn’t mean it can really provide 150A continuous. Beyond several seconds of load the realistic continuous current drops significantly. That is also a problem with 8 and 12s, but it is not as big there. I would highly recommend using 12s.
The VESCs are one of the few ESCs that can take continuous high load without burning sooner or later (because they have current limiting and effective overheat protection). Spending 100-200€ extra can quickly pay off if your cheap 100€ ESC burns up the first time you accelerate. And you get logging and good programmability on top.