That is to say, I do not think the current space for images in /jp/ is optimal for >>3415
Naturally, people will use images to express themselves, or because it's fun, or for whatever reason. That's the norm in imageboards and there's no basis to believe people will behave differently if able to post images in /jp/, whichever the set limit.
I believe the linked thread shows an instance where lowering the max amount of image replies was/would be harmful to the creativity V seeks, that the mindset of treating image replies as precious is not there and that there's no reason for it to be there. Withholding usual image replies for the sake of this rarer funpost is not a good bet, and people will continue to do what's statistically more fun (this is a very awkward line). So lowering or increasing the maximum amount of image replies relative to the population is not conductive to a different dynamic, it will either be as in /qa/ but gimped, or it will be no different in practice except for the lack of image dumping. In my experience, I've seen less emoticons and text art in /jp/ since image replies were enabled, that's something I think can be lost because of images filling their role.
I think the options /jp/ has for a dynamic different from /qa/'s are to either restrict image posting to the OP or permit each poster a certain amount of images per thread (at this point, I'd say just one) instead of limiting everyone based on the thread's total images. The latter might probably also amount to a dynamic identical to /qa/, so I'm not sure about it.
Disregard this post at will, it is silly.