I’ve tried several Raceface Chainrings on my trail bikes of different sizes (32T, 34T, and 36T). These narrow\wide chainrings do an excellent job of preventing accidental chain derailment.
When I first got heavily into the BBS02 I used the old front derailleur which I would adjust to keep the chain from falling off. This worked somewhat but I would still get one or two derailments and hour while riding. I also tried the N-gear Jump-stop which also worked reasonably well, but still I would get about 1 derailment an hour. The reality was that running 1200 Watts through the drive chain with the BBS02 and a chainring adapter the chain-line was so messed up that in the lower gears, it would constantly get pulled off and wedged in between the chainring and the motor casing. I ended up bending two chainring adapters when the motor drive the chain against the case so hard it was nearly impossible to get the chain out of the crack.
The Race face chainrings are shockingly light and still seem to hold up better than I would expect with the BBS02 drive unit. The 7075-T6 aluminum, aerospace grade strength wears down much faster than steel, but to date the only option I know of for steel chainrings is the 28T Surly 58mm BCD. There is no way that a 28T chainring is ever going to fit on a BBS02 without a custom adapter. Surly is talking about providing more teething options in the future so stay tuned.
To mount a Raceface 32T on a BBS02 you will have to grind down the chainring adapter a bit so the chain will settle all the way onto the teeth. You can probably make a 30T chainring work as well but you would really have to grind down the adapter to make it fit and I would not advise it. Although they are marketed for 9-11 speed chains the chainrings seem to work fine with 8 speed chains as well.
The Raceface chainring works well and can be had for between $30-$35 on ebay. As long as you are realistic about how long this chainring will last (probably 6 months of daily riding) and don’t mind replacing it when it wears out, then it is an excellent choice for your BBS02 powered ride. I predict in the not too distant future that there will be more Narrow\Wide chainrings available in steel from SRAM and/or Surly which I would recommend over the Raceface rings for reasons of durability over time.
If you can mount a 42T front chainring you should also consider the Lekkie Bling-Ring which runs about $90. This ring moves the chainline back 9mm towards the bike and is also Narrow\Wide which does an even better job than the RaceFace at preventing chain derailments. The full review and all the info can be found here.