Hi Chris
With bay windows all I do is have the ladder up higher if it's a problem reaching the tops but that doesn't happen very often.
How I use the A frame is to have the top about half way up the side of the frame if there is something for the rubber bit to grip onto.
In the last 16 months I've only twice had 1st floor windows that couldn't be done but they're now done with that rotten wfp thing that we use.
A while back I did a neighbours windows using his ladder which was a bog standard 2 extention ladder. It did not feel stable compared to an A frame. Also, I'd forgotten how close to the glass you are with a standard ladder.