Under CRA Blue Guide concepts, is a personal import after an in-person third-country purchase placing on the market?
No.
The Blue Guide treats that situation as outside placing on the market. It also distinguishes it from products bought online and shipped into the EU, which do not fall under that carve-out.
Supports the answer on personal third-country purchases carried into the EU being outside placing on the market; section 2.3, including footnote 50.