I’d like to note on ‘adding extra encoding for numbers’. While extra encoding might add some burden in one place, it might lessen the burden in another place.
In complex covenants the computed values are often used to compare/combine with introspected values taken from the transaction, and the encoding of that values are usually LE64 or LE32.
In my experience designing covenant scripts on Elements, it definitely feels that there is value in being able to do computations using the same format as the numbers that are stored within the transaction, and with clearly defined ways to detect overflows etc.