I bought some mature tomato plants and have put them in large planter bags as a gift. They have existing flower and a few fruits, I think I should pinch all or some of the flowers to allow the plant to put some energy into root development.

Good idea to pinch all, some or none at this point in the season?

When it comes to pinching, should you :
literally pinch only the flower stamen,
or use a fingernail to completely remove the stamen
or completely remove the flower,
or completely remove the entire stem down to the branch?

Thanks for the advice,