Jenn makes a good point here as in your case defining a digital datalayer object of the impression string i think would be key. You can then ensure its captured in a timely fashion but does seem like you need some dev alignment to make it happen.

So is it that now you are to a more SPA(single page application) like server technology?In that case you would need your page logic to change to capture that string summary later on pageload. Can you verify is it indeed an SPA you are tagging for?

So if you create a data element that looks for a particular link. (Exists or not).   Then map that data element via a page rule to an evar(with expiry on pageview) when page loads.   Then you can just filter pages with evar or not. A prop can work as well but they are usually fewer in number so may ...

For clarity of concept here... Are you just trying to identify a links existence on a page or when someone clicks a specific link/button(making a custom link call)?

Is it possible you are just being blocked by Security settings in Safari? Do you happen to see CSP(Content Security Policy) Errors on this page as well?

No immediate issues come to mind. The fact you use same plugin on 2 different launch properties then makes me think this is just a configuration problem. So I would start compare the 2 launch properties, see if any evars, events or dependencies this plugin looks for are missing in the one not workin...

Can you clarify are these embedded videos or player based videos?   Im guessing embedded? If they are i really recommend the plugin  YouTube Playback You will find often the embed preload would be skipped and in that case the link after click if finally available. things like pause , re plat etc can...

Since you dont have target then you will need either to have   1 devs custom code some banner to geo location based logic 2 use a banner serving tool that does allow geo location       

You would need to perform tests on purchases to ensure you are not dropping any orders.   Did you do a QA of changes and actually test/verify purchases and all related metrics? 

If redesign has caused this to be sure look at things like referring domains, did you lose alot of bookmark and search engine traffic?   Perhaps missing pages need a better redirection strategy if not done so. now