I'll chime in as the only person who does something like this. I primarily dive steels, but on my al80's I have a second boltsnap on, and this is important, BUNGEE cord. It's fairly light, just enough to keep the tanks where they are supposed to be during the dive. I have tried sliding d-rings and reclipping, and prefer this method for open water wreck diving. Does it complicate donning and doffing? Once the muscle memory is developed it adds very little, just like reclipping to a lower dring would during a dive. It's on a light bungee, so the bungee clips in first and then the main lower boltsnap.
It's an option. Is it the best option? No. Is it the best option for me? Yes. I advise trying everything then deciding what is most natural.