ERROR: MonotonicUpperBound requires CapLatestVersion

[oxinabox]

Is there a reason for this requirement?
It seems like it would still be useful to be monotonic except for the latest version.

[DilumAluthge]

cc: @timholy

I think the rationale is, "monotonic with respect to what"? I.e. we are monotonic with respect to the cap on the latest version, which only makes sense if the latest version is capped.

But I see the use case here. We'd need to have a way of saying:

1. Don't cap the latest version
2. Cap the second latest version.
3. Use the cap on the second latest version as the starting point (or ending point, rather) for determining the monotonically increasing caps.