Manual Cron and Multisite Cron

Hi,

For years the wp-cron has been a nuisance on multisite installs.
It runs on page load, slowing things down, and there is virtually no control over it.

Can you please add a simple php trigger that would cause cron to run through all sites, or a subset of sites, by calling the wp-cron.php file.

Having to go domain by domain is really not an option.

Thank you!