It is possible. Not sure how Samsung phones are treated but I do know Motorola phones unless you buy it from Visible it likely will not pass the IMEI checker. How different they treat Samsung I don't know but on Visible's reddit page there have been a few people saying there Samsung phones don't pass the checker or show not compatible. I was told by customer service that even though they sell a certain make and model phone buying it from the manufacturer doesn't mean it is approved and will work with Visible which is not true. They said to me they optimize the phones to work on their network, again not true. Will your phone work? Probably without issue, but getting a card is a different if it doesn't pass the checker.
The phones I know that you can buy elsewhere that will work on Visible and will likely pass the checker to get a card are newer iPhones that are still getting iOS updates and Google Pixel phones such as the 6, 6A, 7 and 7 Pro.
