Hi There @flashfog
Thanks for writing in! You can use V2 elements with classic elements which is totally compatible.
If you want to use certain features in V2 elements, you can convert your classic elements. Otherwise the classic elements should work just fine.
To increase performance of your site, I recommend to go through our performance article on our knowledge base section (https://theme.co/apex/forum/t/customizations-performance/210).
Thanks!