P&G is not a useful method in an EV and will probably result in lower range. Lower amp draw from the batteries will result in more usable capacity. The peukert effect basically says the faster you draw power from a battery the less usable capacity you get. Lithium is a lot better than other battery chemistries for this, but its still a thing. This also lends itself to slower acceleration and lower overall speed.
I would recommend avoiding regen when possible. The energy conversion losses (inertia to electrical to chemical and back) are still there, so its going to be more efficient to not brake/regen if possible.
Electric motors still do have an efficiency curve. It is a lot flatter than an internal combustion engine, but it does exist. Here is an example from a series wound DC electric motor.
I'd imagine AC motors have an even more flat line, but I am not sure on that. I googled for an image and found the small one below. So, this would lend itself to not accelerating too slowly haha.
All in all, all of these factors are MUCH smaller than they are on their ICE counterparts. Where some could achieve 50 to 100% over EPA numbers, getting even 25% above EPA in an EV is going to be much harder to do simply because the inefficiency in EVs is just so much smaller. There just isn't as much inefficiency to improve upon.
Great topic btw!