<font color="purple"> I think the thresholds would look good at the kitchen and hallway, but in between rooms just continue the course </font color>

I just got back online to change my vote on the LR-DR threshold, in favor of one, since the other doorways have them. But after reading through yours, Carl, I think my original thought, and yours, is better...to let the wood flooring run right through. Mainly because in this door it would be with the grain of the floor.

If a threshold is used in this doorway, the floor can be made to match up in the DR-Kitchen door by beginning in the DR with the width the board would have been if the floor ran through.

What do you do with a threshold when the floor on both sides is the same thickness, and no reduction is required from one floor to the other? Just let it stick up a little with a gentle bevel return to each floor?