When you get waitlisted, do colleges require you to send the unofficial grades that you have? Or do they only review the latest official transcript?
Unless they specifically ask for them, which few do, they don’t need or want an unofficial grade update.
Do keep in mind that virtually all colleges will want to see your final HS transcript so maintain your grades at a reasonable level.
They should already have your Junior year transcript and a mid-year report. I don’t recall anyone asking for a 3rd quarter grade report and all waitlists were wrapped up before final grades were out, for my kids.
Schools can vary, of course.