Thoughts on using a PFC module + Incandescent light bulb as a 400V CC/CV charger

[globoy]

As part of an EV conversion project I am making a small (test) HV battery: 97S @ 6.4Ah (2.3 kWh - 360V nom, 407V max).  It has a BMS providing cell balancing, input/output current monitoring and other functions but I need a way to charge it.  The BMS will provide charger on/off control so what I need is a smallish CC/CV power supply capable of putting out about 407V.  I'm happy if current is 500mA to 1A as charging speed doesn't really matter.  I don't want to break the bank so buying a lab supply seems more than I want to spend.

I have been wondering about using a PFC correction power supply in series with an incandescent light bulb.  For example something like this TI PFC Eval board reconfigured to put out slightly higher voltage and a 60W/120V light bulb.

Eval Board https://www.ti.com/lit/ug/sluuat3b/sluuat3b.pdf
Chip Spec https://www.ti.com/lit/ds/symlink/ucc28180.pdf

The Eval board specs are 390VDC @ 0.923A max.

I will always charge the pack before its voltage drops below 330V (3.4V/cell).

Google's AI tells me that a 60W bulb has a warm resistance of 240 ohms and a cold resistance of 24 ohms.

I think this means that during start-up the PFC controller will have to limit current as the bulb warms to a steady state but the TI part above seems to be able to do that. 

This circuit is non-isolated but the pack is isolated and I also have a big 120VAC isolation transformer I could use (especially for testing).  For the faint of heart, I'll be taking good HV precautions (covers/insulation over all HV wiring, fuses, disconnects, HV contactors, battery in a box, etc).

I'm a digital/low voltage guy and am curious to hear some more experienced engineer's thoughts about this idea, modifications to it or alternatives.