Great suggestions, as long as the added HubSpot functionality comes with the clearest of warnings -- e.g.,
“Modifying these settings can break HubSpot functionality!” 
Hi there, this is the biggest thing holding me back, I’d like to stay updated. HubSpot Support responded to my optimization efforts saying they already provide AMP for mobile, http/2 and page caching. But every time I test landing pages they come up uncached and it’s killing the speed. So It seems the BLOG pages are optimized, but the LANDING PAGES are not. Unfortunately, we have no need for a blog, but urgently need OPTIMIZED LANDING PAGES.
I’m looking into manually coding each asset to lazy load to offset the issue, and even that is cumbersome, I can’t believe I’m not given a choice to have lazy loading with the cache issues I’m running into.
I’m challenged with the same issues. GTMetrix gives top grades down the line but fails for “Leverage Browser Caching”.
I’m not a developer, but focused on site rankings, running audits via semrush, etc. The page load and speed affects other objectives downstream. If anyone notices an opportunity for me to improve this on my own, please lmk.
