Two engaging abutments for 3-unit implant bridges?

Cases and Questions
#1

Regardless of internal hex or conical connection, as the walls/surfaces of the implant hex parts are all parallel and not tapered, so if you are using two engaging abutments for 3-unit implant bridges, how do you get passive fit? Or we should never use two engaging abutments for 3-unit implant bridges?

1633479391084-ScreenShot20210929at12428pm_25289.png600×532 187 KB

#2

Tim Carter comments:

If using engaging abutments it must be a cement retained restoration for the obvious reason stated. if you are set on doing screw retained multi unit restoration than it needs to be on either tapered/multi unit abutments or non engaging.
#3

Greg Kammeyer comments:

Using CAD/CAM custom engaging abutments will give you parallelism. Non-engaging abutments can be tough to align properly with the prosthetic.