As far as I know, the grace period for edits is 5 minutes, and it doesn't matter if it's a normal or a suggested edit.
I proposed an edit for this question and later on, well past the 5 minutes, I noticed I didn't correct a spelling mistake on the title.
Nonetheless, I clicked on edit and my suggestion summary was intact and I assumed that fixing the title wouldn't count as another suggestion. Is it right? Did I only propose one edit or was it two suggestions?