I think having a way to incorporate spectrograms would be useful, but that doesn’t change the fact that, currently, they are discouraged and cause issues for training the CV model - including them with observations could actually reduce the ability of the CV model to accurately identify the target species.
You asked for options for making spectrogram data available for observations, and staff did provide some alternative suggestions for how to include this data with observations in the link I quoted previously:
There are a lot of free image hosting services online that could be used to create links to add to your observation, so you could consider that.
In terms of adding functionality around spectrograms, @thomaseverest posted a link to a feature request to add spectrograms to sounds above:
you could also consider making a different feature request if that one doesn’t meet your needs/desires. Feature requests are the process by which many community-suggested features have been added to iNat. That said, there’s limited staff/development time for adding new features, so many are not added or take some time to do so (but you don’t know until you try!).