Sorry; what I was getting at is that, in the TB20 I fly, opening the gull wing door at a high speed might rip it off, which might not do the elevator or the VS much good... So if one wants to chuck something out, it is best to slow down as much as possible. Early TBs have the little "draught" window but not mine.
It should be much safer to open the door on a Cessna or, if you have a co-operating person in the RHS, on a Piper, but you still need to slow down considerably.
IMHO, and obviously never having done it, if I had a smoking battery I would initially unplug the battery and try to chuck it out, or chuck the whole laptop out. One would not try shutting down windoze
The cases of burning batteries appear to be caused by an internal short (a penetration with a sharp object is one way to do it) and nothing you can do externally is going to alleviate the situation. Once it goes off, it goes off.
There is actually another option for LIPO batteries which is to use the protective bag shown in this
article. They only cost a few quid and should contain a fire in a small battery (but not the smoke). I carry one of these, tucked behind the liferaft. My son is into model flying so he has loads of them.