I have to admit to being astonished that this is supposed to be a "good thing" where African hunting is concerned.

The majority of hunters doing the conversion to the Lott chambering for use on big game in Africa will most likely be doing it on a bolt action rifle.
So, someone takes a 458 Lott bolt action rifle to Africa to hunt dangerous game, their ammo gets lost and they opt to use factory 458 Win ammo.
Bolt action rifles to be used on DG MUST have their magazine/action rails/follower/spring/feed ramp regulated to feed their cartridges perfectly.
Their 458 Lott magazine is now WAY too long for the 458 Win ammo!
Their 458 Lott rifle is (should be) set up to feed cartridges which are WAY longer than the 458 Win they now intend to use!
Their 458 Win cartridges have heaps of room to move wherever they want in the mag during recoil!
This is exactly what you DON'T WANT in a DG rifle!
There is a real good chance that the shorter Win 458's will not feed properly in a mag that has been set up to feed the much longer Lott cartridge!
Instead of a dangerous game rifle you could really have a DANGEROUS RIFLE!

458 Win in 458 Lott chambers?
An option yes, but IMO maybe not a smart one where dangerous game is concerned!