If such an app presents itself on Shopify, I'll definitely consider it! Unfortunately, I have zero coding knowledge of any sort, and don't particularly want to commission such a thing, as it will require maintenance I'm unable to personally perform. I would be placing some major limits on a cart hold system (IE only a 3-minute hold), as I don't want people to be able to easily juggle product for hours while they make decisions, but I'd like something that allows people to grab one or two big items and the accessories they want and get out efficiently with them. I can foresee potential issues with bots, so I may change my mind in the future if people can't behave themselves and resort to unfairly using bots against regular customers.