Last December our flight from home to Vegas with WGA no EBCI was B24 however the flight home from Vegas I had gotten B60 right on the dot, it was however the latest I've gotten ever (other than a random glitch when we had Companion and I ended up with a C back in like 2017).
When we went to WDW in May my husband was A-list, I was on a separate reservation with EBCI purchased (reimbursed through the CC) with just WGA and it was A40. On the way home with EBCI also purchased for me it was A34. We used the EBCI benefit for this one as it runs on a June/July (can't remember) cycle.
When we went to Vegas in September we were both on the same reservation so I was getting his A-list benefit and my position was A20 on the way there (keep in mind it was a 4:40am boarding time though) and on the way back home it was A28 (a 8:45pm boarding time).
It can be all over the place, for us we typically take the early flights and the late flights to places. When my husband travels for business typically early to mid-morning with afternoon to late evening flights depending on non-stop vs connections.
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You could see if you felt like purchasing the Upgraded Boarding if that is still available for your flight, that would be any leftover positions between A1-A15.