If you look at the spec sheet, you should be able to do a 48v pack with 14 cells.
What I found interesting was the deeper discharge with no worry of cell damage.
That would give you a voltage range of 55.3v to 21v on a 14s "48v" pack...though I don't know how a 48v motor would perform at voltages say below 36v.
And if I'm reading it correctly, the continuous discharge rate seems less than the typical li ion so more cells in parallel would be needed to match performance.

I was surprised to see that sodium ion cells are available from sriko, a US based seller

They are only 3.0V. Probably need 16 cells in series for 48V. And the capacity is about 2/3 of Li-ion. I did some numbers and the tradeoff is about a 2.4X increase in size for the same capacity and voltage, ignoring any weight changes.

Seems just as feasible as the LiFePO4 cells. Maybe we'll see them soon in bikes where battery shape/size doesn't impact the styling, like cargo bikes and trikes.
thanks harrys.
Micah is a nice and knowledgeable guy... But the build videos I watched left me thinking.... Hack.
I've seen much nicer builds on this site by some.
It was once about a dreamy eyed engineer from Israel. Now an electric construction equipment dealer.

Micah didn't endorse the Vruzend kits, he was a part of the company. Which has now disappeared. I have a bunch of them gathering dust.

It's the endorsement of cheap eBikes that turned me sour. WTF?!