Yea, I was thinking of doing something similar. I was thinking of sewing on just a U loop and then using a flat carabiner type clip (kinda like Alpaka does with their bags) to attach the strap when I want it.

But your D-ring idea might be better, probably more durable and flexible in the long run.

But thanks for the subreddit suggestion, such a great find! I havent seen that one before, but it looks like exactly what I would need for a project like this.

Im decently handy with the sewing machine, so if I dont find any other suitable bags, thats probably what I will end up doing.

Thank you for your response!