@jwoltman
Although I haven’t yet tried the Async Image Decoding plugin, since it is currently free to download from https://marketplace.getpublii.com/plugins/image-decoding/, maybe just give it a go.
Looks like it just adds the ‘async’ attribute to anywhere in content pages that it finds an image. Since the current Publii image galleries in the current themes at https://marketplace.getpublii.com/themes/ are installed on to content pages and do have image ‘src’ code markers for each gallery image, I would expect that the plugin should work with Publii image galleries too.
Having said all that, while this plugin won’t reduce the size of bloated source images — or images that are not optimised for the web — Publii itself includes code that does a good job of helping to optimise images for use on its websites. So you might find it works well for your site. Sometimes, the only way to know for sure is to test with the plugin installed and without the plugin installed then compare the difference.
