I have a hallway with three bedroom doorways. The wood flooring will run length way down the hall and across the door openings. The bedrooms are currently carpeted. I am planning to end the wood flooring under the doors, splitting the difference. I have not yet undercut the door frames.

I see no need to undercut the door frame beyond where the wood floor will end, as it would be too high on the carpeted side, (the flooring is 3/4") although that would be the easiest approach.

How is this situation typically addressed by you pros? I am thinking of notching the door frame where the wood floor will end using a multi-tool. Is this the right idea? Thank you for any tips and insight offered.

Pics would be very helpful if any body has them.

Multi-tool will work well for this. Under cut to the carpeted side of the door stop so that when you are in the hallway and the door is closed you will see the wood floor and when you are in the bedroom(s) you would see carpet. Yes, no need to undercut the frame beyond where the wood will end....undercut is there to allow the wood to 'disappear' under it.