From the southern hemisphere, I’d predict around 8:28-29, and here’s why.
A useful comparison is between Spencer and one of our Australian junior standouts, Kieran Shepherd. They raced each other at World Cross Country over 8km, where Spencer finished roughly a minute ahead.
Fast forward to February 28, and the 16-year-old Shepherd runs 8:00.24 for 3000m, which converts to approximately 8:34–8:35 for 3200m. Given that Spencer is older, more developed, and likely stronger aerobically, it’s reasonable to project him dipping under 8:30 based on that benchmark.
I do agree the field is quite crowded, but it’s worth noting that Shepherd ran his time in a 25-athlete field at our National Open Championships so a big race doesn’t necessarily prevent a fast performance.