Thanks for your question. Without getting too into it, there were a number of technical reasons that they moved away from the Allow List Only option a few years back. While I don't have anything to share regarding the possibility of an Allow List Only option at this time I will absolutely submit your request formally to my developers. They do regularly read and consider requests like this and it gives them an indication of what our members are looking for in the services we offer.
Thank you and have a great rest of your day.