Manual 5-Second Video Background Removal

I have a 5-second clip of a person standing still that needs a flawless background lift. Automated tools have failed me already; bright, distinct whites in the scene confuse AI and make chroma-key unusable. I therefore need a frame-by-frame or rotoscoped cut-out done by hand (or with pro software features such as Mocha tracking or After Effects masking), not by a one-click web service.

Deliverable:
• Clean, transparent-alpha ProRes 4444/PNG sequence, or the same shot composited over a pure white background—whichever you prefer to supply.
• Result must be free of haloing, flicker, and colour spill on every frame.

Please let me know which software you plan to use and your turnaround time so we can lock this in quickly.