Thanks @mark_pmw I volunteer to herd the framebuilders.
Let’s start with technical criterion:
Tapped vs untapped cone?
- Tapped is simpler to build and adjust the fixture (1 single bolt required)
- Untapped is more flexible and probably cheaper
Max diameter?
- 44mm HT?
- IS52?
Min Diameter?
- 27.2mm seatpost?
How many sizes?
- one cone fits all?
- Small cone: 25.4 - 35mm cone
- Big cone: 35mm - 50mm cone
The angle of the cone?
- Steeper cones grip the tube more aggressively
- shallower saves material (cost and weight)
Do we creep the scope?
- BB pucks
- HT pucks
- purge holes and fittings