youngoldbloke
The older I get, the faster I used to be ...
I can imagine; but if there is little/no flat, you might have an easier life than "the group" I think?
Yes but mostly no. it's the false flats that are the most difficult, long smooth stretches where the speed drifts up, and once dropped it's well nigh impossible to catch up if no-one notices. Undulating routes are the best, as long as the flats are not too long, you can get back on on the hills, but it's not a very satisfactory way of riding. Perhaps unexpectedly long downhills can be hard work too. Most times of course folk are more accommodating, but sometimes some will 'go for it'!