The main thing to consider is what you intend to do when accessing the lounge. AS does not have lounges with extensive gourmet food buffets, spa services, etc. so it is unclear how much you would really gain through the entry and whether buying a refundable ticket and refunding it would be worth your time.

That said, people buy and cancel refundable tickets without issue. WN even uses that as a selling point for their business select and anytime fares which can be refunded directly in their app up to 10 minutes before departure time. Quick and easy. Some people need flexible tickets as they may need to change destinations or some business negotiation, legal action, etc may be delayed or cancelled--or may even be even meet somebody in a lounge. Not a big deal at all.

If you are regularly buying refundable tickets for the sole purpose of entering a lounge, this is where you can get into trouble--but again, an AS lounge is not worth the trouble if you are just looking for some space or food.