FIBOFTF — hasPercentageAmount is semantically flawed

A percentage only makes sense as a percentage of some other value. FIBO is missing the notion of the other value.
For example a fee expressed as a percentage is (implicitly) a percentage of some amount. But for common occurrences such as a management fee that is "1% of value invested" a lot more precision is needed as to when the value is taken, currency etc.
In fact percentageMonetaryAmount definition states "A measure of some
amount of money expressed as a percentage of some other amount,
some notional amount or some concrete Money Amount" with an editorial note "This will have a relationship to what it is a percentage of.
Alternatively and for some applications of this term, there may be an
enumerated list of possible things it is a percentage of."
However there is no such capability provided that I can see.

hasPercentageAmount is semantically flawed

Percentage is only used when it is already a percentage OF something. When we come to the places where percentage is used, we can add assertions in those specific models, we can add some assertion to show what the percentage is a percentage of. MB will do this for Indices and we will see whether we have all the bits we need in Foundations to support this.