See https://github.com/lodash/lodash.github.io/issues/45 I did some profiling and we're doing layout for a while on pageload, as far as I can tell. Also as far as I can tell this depends somehow on both the fontawesome stylesheet being included _and_ on the flex styles being used. Removing either one makes things much faster. I expect that we're reflowing multiple times because of the flex thing; not sure why the fontawesome stuff comes in, but maybe something about its generated content stuff? Daniel, do you have time to look into this? I'll attach what I think is a self-contained version that shows the problem (and in particular doesn't have any of the scripts from the original page).
Attachment #8788712 - Attachment is obsolete: true
Note that Bugzilla is being really slow, at least for me, so you may need to download those locally and edit them to point to file:// URLs to get useful timings not affected by the server and network....
I've got a backlog of stuff I'm working through right now, but I'll try to take a look at some point next week. [leaving needinfo open]
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