Hey there, @lyasick . Thanks so much for taking the time to write into the Shopify Community regarding your address question!
First, the person you spoke to previously was correct. At this time, there isn’t a way to increase the amount of addresses shown in the checkout. A few years ago, we did show more addresses, but this was a change that was made back in 2019 to help with loading the checkout/presenting a cleaner checkout experience.
However, we do know that sometimes, these changes are good, but they could be better and improved. I’m happy to pass your feedback and suggestions you provided here to our Product Team for their consideration. I can’t promise what the result of sharing this feedback may be, but you can trust the the team is aware of your post here, and the ideas that you’ve shared. I know this isn’t a solution, but I’m hopeful that this helps you remain optimistic that improvements may be coming down the pipeline for these saved addresses for customers.