Well, if you invented it, you're not the first. There's a smattering of Google hits, including some from texts that appear to have been written by educated native speakers. Sometimes it's spelled "nuanceable".
"-able" is a living prefix, so it can, in principle, be applied to pretty much any transitive verb, albeit with differing degrees of viability, depending on the verb.
Clive, I mean that the panegyric could be interpreted, we should consider some differences. The person who wrote the panegyric might not have been 100% objective.
The word 'panegryic' by itself tends to imply that the writer is not 100% objective. It also suggests that the words are so strong that they do not have nuances, which are subtleties.
Finally, the term 'nuancable' only suggests that something is capable of being given nuances, If you want to say that something actually contains nuances, use the word 'n