Looking to pre-qualify users before checkout - ensure they are from a state we ship to

Hi,

wondering if there are any apps or if anyone has found a solution to pre-qualify users when they arrive at a shop. For example, the shop I’m assisting, certain products only ship to certain states in the US. As it stands, the user only finds out at checkout whether they are in a valid state or not. Obviously this would be frustrating to add items to your cart only to find out at checkout that you can’t have them delivered to you.

We can write notices ‘we only ship this product to x, y, z’ but a lot of people miss those and then get frustrated at checkout.

One idea I had was to create a custom filter including all states. Then we apply state tags to products to indicate availability. Then we activate a pop up on arrival asking the user to ‘select your state to see product availability’. I think that solution would work, but wondering if there are any others I might be overlooking.