There might be some minimum server specs:
But it is hard for us to give this as it depends on so many factors that are related to your repository… And as we mentioned before, there may be pain points in different areas (first load, content load, items request, filters request, image load…)
For now, you can try out our development version where I implemented the dynamic loading of view modes. If you only have the necessary ones enabled in the Collection/Block settings, it should help a bit with the page first-load:
Remember, when installing new versions of the plugin like this it is always good to give a full page refresh (CTRL+SHIFT+R) to get rid of cache from previous versions.
This should only affect the javascript load time. About the API requests, I just noticed that you have a considerable amount of filters enabled. One thing that you could try is to set some of them (the ones that you consider to be less relevant) to “Begin with filter collapsed”. This option avoids the request to the facet values until a user goes there and expands the filter on purpose.