This performance conundrum reeks of excessive (incidental) complexity. I've warmed up to Javascript over the past 15 years, but forcing website authors to concern themselves with such details becomes less and less appealing and grows ever more ridiculous. I hope the future of HTML+JS will involve to a better way.
I thoroughly enjoyed the spiritual essence and relative purity of HyperCard at the time in the 1990s.
Edit: @ly: Apologies, I should have been more specific and clear.
Referring to the complexity matrix in terms of what may or may not cause page rendering to block at any given moment. Complexity in this location all but ensures you will make a suboptimal decision during development unless you run every release candidate through Google Page Speed.
I thoroughly enjoyed the spiritual essence and relative purity of HyperCard at the time in the 1990s.
Edit: @ly: Apologies, I should have been more specific and clear. Referring to the complexity matrix in terms of what may or may not cause page rendering to block at any given moment. Complexity in this location all but ensures you will make a suboptimal decision during development unless you run every release candidate through Google Page Speed.