I was packaging an app of mine as a web bundle to test this format https://github.com/gaycodegal/LizardUp/releases/tag/v1.0.0 and found that the web bundle was much larger than I had expected. This turned out to be because I had recently been doing git history with large files, and so my .git folder was larger than the rest of my app. Given many web bundles are likely to just be packaged up github projects, it would probably be wise to not include the .git or any other hidden folders by default, and have these have to be specified manually. Creation of the web bundle was done using the following command:

~/go/bin/gen-bundle -dir LizardUp -baseURL https://gaycodegal.github.io/LizardUp/ -primaryURL https://gaycodegal.github.io/LizardUp/ -o LizardUp.wbn