Sorry about the confusion.
Normally I would make DVDs of under 20 minutes which I know is perfectly possible.
However, I never completely trust what I am told as often “common knowledge” can be “common error”.
I like to experiment to discover what works for me.
So although I do not intend to make long AVCHD discs as a matter of course, I will be experimenting to see exactly what and what can’t be achieved on a DVD-5.
As I have not yet got the BD player, I wanted to know whether anyone had actually checked to see what the limits might be, on the understanding that quality will inevitably suffer.
As I suggested earlier, I have discovered that with suitable subjects, it is possible to get good results with remarkably low data rates.