SharePoint Forms

What are people using to design custom forms in SharePoint? We have used InfoPath and recently we purchased a Help Desk package from SP Marketplace and that template uses Dynamic Forms. I have heard that InfoPath is going to be discontinued (whatever that might mean) and I am wondering what others are using to create custom forms...including tabs with fields that show up based on choices...any ideas, suggestions, etc. would be appreciated. Thanks to all.

Help with list view threshold error

I am sure we have all encountered the list-view threshold limit of 5000 items many times. However, this is a scenario I have not encountered: We have libraries that exceed the threshold limit that the users have organized into folders. I am recommending splitting these out into different libraries to keep below the threshold but Microsoft articles advise that this is a reasonable way to manage large lists.

Here is my problem: what if I want to change the URL of the site? When I go to change the site title and URL I am hit with an error prohibiting the operation due to exceeding the 5000 item threshold. I assume that this is because SharePoint is updating each list item with the new site URL as the path for the item is a hidden metadata field.

Are we expected to never change the site name if we have large lists or am I missing something? I will get around this issue in the short-term by splitting the library but I am unsure what to tell future clients, especially since I can't find any articles on this specific issue online.

Please provide your suggestions / advice / recommendations by means of COMMENTS