They're interesting guys, but FFS their 'number one challenge' in heat loss, has a number one answer: insulation.
I'd also suggest that anyone trying this at home without overcoming that challenge could try to distribute any added heat throughout the entire mash, not just the liquor.
I think it takes him an hour longer compared to extract brewing, that seems to be the implication.
Sparging is an 'option' all right, but deciding to sparge isn't equivalent to just using conventional 3V equipment (16:24), there's many other benefits- did anyone notice how hard it was to lauter and how few pieces of equipment there were? Sparging doesn't take longer either, I can't understand why that keeps coming up on the cons, the sparge step takes place while the kettle is coming up to the boil, it actually takes advantage of the time where you would ordinarily be standing around picking your nose anyway. However, in the stock/ no- sparge BIAB, which I'd suggest novices should be doing first, it becomes moot.
Nevertheless, I'd recommend the video to interested brewers as an intro with a demo and discussion around BIAB. :icon_cheers: