I've only seen a mention of it being a Livewire record, not fastest electric overall.
The article you linked has this quote "Sampey set new records for elapsed time and top speed by an electric-powered production motorcycle on a drag racing course."
Energica has not done any official 1/4 mile runs with the new 21.5kWh bikes. No idea if Zero has taken an SR/F or SR/S to the strip? Something tells me that this new Harley's record will not last very long...
Regarding the OP's questions about running an EV moto on the drag strip.
If you have done passes before on a ICE bike you will find an EV very easy; no clutch to slip, no gears to go through.
I found it very easy to build a rhythm at launch to get very consistent times.
You want to run the highest tire pressure you can to reduce rolling resistance, so long as you can put all the power down.
Running stock tires the 2018 EGO I ran never broke traction on launch even with 38psi f/r, prepped surfaces have a LOT of grip.
I would do the first run with TC on to see what that feels like. If might be necessary to switch it off depending on how much it intervenes.