Hi Bill
I would highly recommend not using BLO on top or under any film finishes. As a way to " pop the grain" under a finish, it is very difficult too know when this stuff is dry enough to coat. It tends to fill the pores so the finish can't bite/penetrate as well as it could. The reason you thin the sealer coat is to get the finish as deep as you can into the wood. Stain/dye is much better for popping the grain and has a long term effect. Oil under a film finish will create different surface tensions and can accelerate finish adhesion failure.
On top a film finish, it serves little purpose, has a long dry time , in witch to collect dust, and continued use over time can darken and/or create a sticky or gummy surface when heated.
Last week I spent some time removing BLO from the surface of a great little drop lief table [ early 1800's]. The table sat next to the window and when the sun heated it, things would stick to it. Their computer left marks and paper bits were embedded in it. Kind of a goo. How do I know it was BLO? They showed me the can their grandma gave them when she let them have the table.
I've been finishing and repairing finish for 30+yrs, I don't have any BLO in the shop. It's good for making paint and dipping fence posts.
History books are full of uses for BLO, Time has shown there are better ways to finish wood.
Do Good Work
Randy