This is the very reason the .375 anf .400's exist.

However deprends on the shooter and if they are capable with the .458. Only way to find out is to actually use it for medium game a lot and at different distances. And failing that at paper targets.

In Australia years ago when ferals were far more common, hunters used to "practice" with their big bores on feral pigs shooting often hundreds of them before a safari.

However I don't think I would like to have to take long range eg 250 plus metre shots with a .458 Lott, especially if using prone or similar constricted rests. I think one will be restricted to standing shots uising sticks and sitting shots.