BMS Protection For Cordless Drill - Diode and Capacitor

[J_C]

I've rebuilt a battery for a 14.4V Dewalt cordless drill, DW991.  It has a brushed DC motor, probably about 250W, variable speed (same old biased transistor trigger module), and reversible.  Battery originally NiCd, now Li-Ion.

I've put a BMS in the battery pack and the datasheet (which lacks a schematic of the BMS itself) states:
https://www.mantech.co.za/datasheets/products/BMS-40A-4S_SGT.pdf

Note 3: When the load of the brush motor is used, try to connect a non-polar capacitor (withstand voltage above 25V, capacity 10uF-100uF) to the motor's positive and negative terminals to prevent the reverse spike from the motor. Break the MOSFET's.

I don't happen to have any non-polar caps with a uF rating that high.  Can I just put a couple 100uF polarized connected back to back across the supply leads at the motor?  Since they start the suggested range of capacitance at 10uF, would two 20uF polarized back to back, be sufficient or is higher capacitance going to matter in this application?

The datasheet makes no mention of a flyback diode but would that be a good idea as well, between the battery and speed controller (across the supply lines, not in series) since it's a reversible drill,  or do you think that is already built into the speed controller or that it effectively negates the need for a flyback diode?  If adding a diode would be beneficial, can it be something like a 1N4001 or do I need a fast recovery or schottky, or higher current rated than 1A?

The BMS PCB already has a diode across the output as seen on the top right of the picture below, so would adding another just be redundant and no point in doing it?    I've attached a picture of it and a "possible" schematic of the BMS but I have not reverse engineered it to know for certain that this schematic is correct, though it does not have the diode as pictured on the PCB, which is a bit odd as it came from the following site which claims it is "complete":

https://circuitdigest.com/electronic-circuits/lithium-ion-battery-management-and-protection-module-bms-teardown-schematics-parts-list-and-working

[elektryk]

There's probably a diode already built into the switch.

[J_C]

Yes I can check for that, but  nobody has any thoughts about the protection cap the datasheet mentioned?

I'd watched a few youtube videos of people converting cordless tool batteries but don't recall anyone adding that cap, and while I haven't torn apart a lot of Li-Ion powered tools and batteries, don't recall seeing that type of cap on them from the factory either, at most just some little, maybe 0.1uF ceramic on the motor terminals for electrical noise reduction.