From experience escalating other projects, he's probably at the stage where the urgent (the site collapsing) is done before the important (delegating tasks). If he stops to delegate tasks, the normal functioning of the site will collapse.
Anyone who wants to volunteer and don't know where to start can start by going to the currently opened PR and reviewing them, testing them, improving them. Of course @ernest will have to review them afterwards. But if three independent developers say they already tested and reviewed and reported the potential mistakes, that makes his life much much easier.
sab
jwr1
Zariah