You can throw the bike around with quite a lot of weight on it, but that weight cannot be anywhere near the back of the bike. The further back it is, the more leverage it has over your handlebars and the harder it is to control with your wrists. Put that weight in LowRider panniers and you will find it has almost zero effect on the bike or your hands when you rack it out of the saddle.

When I tour, all compact heavy stuff goes up front. Bulky stuff in back, (I have toured with four front panniers, no large ones.)

Ben