I think the thread has been pretty tame in light of the fact that the topic involves gun safety which often {should?} generate in-depth discussion. If I have caused consternation in any way, I do apologize.

Hoppdoc, as a sort-of answer to your inquiry, I don't expect big-bore and/or double rifle design or carrying convention to change anytime soon, but for my needs when skiing or when I need both hands for something else, am hiking in very steep country, trapping and/or just getting one place to another and don't expect a shot {as on a long hike at night or before dawn}, I have made various double-sling affairs over the years that make carrying any rifle much easier. I've modified rifles also and frankly, for pure efficiency, that's best.

This winter I have been testing a "universal" doublesling rig I made. It fits any rifle and does not require the rifle to be modified to left-side {opposite the bolt handle, rt-side for left-hand rifles} sling attachment.

Here is the Universal Rig:

A simple double sling arrangement here, though I prefer the left-side carry as it is smoother on the back:

Some rifles have a left-side setup already, and this works well: