Sorry if this has been asked a thousand times or the information is readily available – I just can’t seem to find a definitive answer.
I have a small classic SP site that uses classic DFFS/vLookup to have forms with tabs and relate data across lists. I use some custom JS and CS defined in the DFFS config but nothing extreme. I don’t use any kind of workflow, emails, autocomplete, cascading dropdowns, etc. – its really pretty simple as far as all that is available in DFFS.
Bottom line. Are there any hard deadlines where this site might stop working because MS is deprecating some feature of classic SharePoint?