hiker;
It sure will got hot! but no stirring really needed for what he's wanting to do.
Using it has heat exchange to pre-warm DHW and gas production he'll need to keep the temps up in the 150F range.
The fertilizer will be a added plus, BUT you are correct he will need a way to unload some while the pile still works, but depending he may not need a way for the first year.
Will need some veggie garbage too, very little gas production with just brown leaves or grass clippings.
And it could take a lot.
Top capping could be a build up problem so a simple stirring of the top portion will help a ton. it's 2 years on since I put our little one up and it's still going.
By little I mean 4 foot wide by 4 foot tall.
The stuff at the bottom is warm even in sub freezing and snow, makes tomatoes really grow too.
Cheers
Bruce S