Do not sacrifice UX for SEO. Good SEO is good UX.
Knowledge usually derives from past experience. Many past SEO tactics and strategies are obsolete and counter-productive knowadays. Be careful your agency isn't pulling the wool over your eyes or obfuscating -- the only SEO is SEO that brings quality inbound traffic to your website. The only CRO that is effective is CRO which increases your conversions. Both SEO as well as CRO should not be seen as independent of the User Experience. They are part of it.
The single most important SEO ranking factor: accessibility of content.
Accessibility includes site structure, the link profile, and the form and organization of the content itself. More: A Guide To Search Engine Optimisation and Web Accessibility
Likely, you've heard advice to "pick the low hanging fruit". You've definitely heard this if you've ever worked in Sales, Marketing, or Management.
The advice, however, to actual fruit-pickers, is absurd.
The agricultural industry has always advised against picking low hanging fruit. Low hanging fruit is usually the least ripe or the most rotten. Not only will picking the high-hanging fruit first make for higher quality fruit in your basket, it will also allow for easier collection of all the fruit on the tree more efficiently. www.fastcompany.com/32746...
Take the advice from the Agricultural Industry -- Never collect the low-hanging fruit first.