It could, but it doesn't. As many have remarked already, it appears there is a bug that's causing the site to reload Google's recaptcha multiple times.
This is a big low hanging fruit fix, another is simply minifying the Forum's JS, there is also bound to be a lot that can be done on the Nim side to reduce the code size generated.
As far as I can see you already have a minification task [1] in your nimble file. May I ask you why you are not using it to save bandwidth both for your sever and your visitors?
This is a big low hanging fruit fix, another is simply minifying the Forum's JS, there is also bound to be a lot that can be done on the Nim side to reduce the code size generated.