yes, mostly I leave in 3rd, except it's damn fun to change through gears sometimes and freeway cruising I move it into 4 gear. It's like owning a manual and auto at the same time. First and second in an electric car is really a blast!
I don't have 0-100km figure yet, but goes super hard, instant torque, it sits and handles well and still has original 5 speed gearbox, but I usaully just leave it in third gear.
With my MGF EV conversion, I retained the original heater core and pipes, as I really did not want to dismantle dash to get to heater core. I bought a water heater tank (HV) from friend second-hand and behind firewall, plumbed this into existing water heater pipes. to turn-on I used the demister button which has never been used on my soft-top. Heater works really well and heats up the cabin like traditional MGF heater. But really the best thing I installed was heated seat kit off ebay, it draws very little power and warms up your behind nice and quick, some photos below.
I'm from Australia (Geelong Victoria), I have owned my MG-F since new in 1999, back in 2015 the motor died and I decided instead of sending it to scrap yard or selling with a blown motor I would try to convert to 100% electric, lucky I found a local group of EV enthusiasts who helped me with advise and help, I did not have any engineering or electrical background before diving into this project, but happy to report my MG has couple thousand KM's on it now as Electric and it drives amazing well... very zippy
Battery: Nissan Leaf battery pack, salvaged from Japan wreck
Motor: Siemens Azure AC induction 3 Phase, capable of 150kw, 300Nm torque
I have some progress photos on my website below + specs, if anyone has any questions, happy to answer.