That is mostly for safety warnings, eDJ, as far as I know.
I had a look and could find surprisingly little, even in Spanish, for wait times north to south/as affected by Mexican customs actions. Almost everything I found, in Spanish or English, was drawing from the CBP website/app (
https://bwt.cbp.gov/), which show only times coming back into the US.
If somebody
really needs this info, bad enough to look hard for it, you might have some luck with
(1) Facebook groups,
(2) Google search specifying News and Tools>Recent>24 hours (or whatever time frame you want),
(3) maybe webcams for specific crossing points.
Especially for Facebook you might search on the destination in Mexico (eg Algodones, Baja California, Rocky Point) because there are probably groups for US people who visit those places regularly.