[atlas] ASN in probe application page vs. probe ASN status / dynamic ?

Sorry for the title gore, hard to summarize this in one line. I was wondering why does the application page ask for ASN, if once the probe is running and connected the ASN is automatically determined ? I just had to flip my home internet to our backup provider and after a bit my home probe changed it’s ASNs as hoped/expected. If this is dynamic - why even ask on the application page ? Thanks. PS: Talking about a software probe here in case that makes a difference.