- don't think so
請問,在拿到收據之前可以申請F1嗎?
- you may apply to change to F-1 at any time, but most likely the petition may not be approved after submission of I-485 regardless you have the receipt or not.
如果申請F1被拒,後果會很嚴重嗎?
- when only looking at the F-1 denial, you're fine as long as you have 485 pending
More info on F-1 and I-485