Firstly, if you like the other script why not use it? - its perfectly workable…
The trick for having more than 100 items is to have multiple CMS collection on the page and having them display only part of your CMS collection each (see Step 2) – you just have to make sure that they have same names. Also, you have to set the collection up so that first displays you cms items 1-100 second one 101-200 and so on…
if you chose to use Siderfy script then you should look at its api to get an idea on how to further customize it.
Finally, I am not sure why your icons pop… try testing different browsers and in incognito mode - I don’t have this behavior…
P.S. you can also clone this page and I think it has a working script like you wanted…