> The biggest issue I see is that those models (or rather their trained parameters) are usually pretty large (several GiB). So it'll take a while to set up in the browser before the evaluation can actually start. It'll also require a lot of bandwidth on both ends.

Might not be feasible due to memory constraints (I'm not sure), but browsers can load data from disk into memory without having to touch the network. So you could in theory ask the users to download the model separately, then ask them to select it from a file picker, and the browser can have access to it that way.