The current rendition of u1A6B is uncomfortably small. Not by much, but enough. Notice to contrast it with U+1A65 it is designed on a slope. Thus:
sorry about the ugly image.
shaping
It's AP is then most easily positioned to the right such that it hangs to the left of the centre AP used for normal vowels or the tone mark U+1A75. The aim being that it can co-occur horizontally with U+1A75. But that means two glyphs attaching to the same AP. So U+1A6B probably needs its own AP. Sigh.
The current rendition of u1A6B is uncomfortably small. Not by much, but enough. Notice to contrast it with U+1A65 it is designed on a slope. Thus:
sorry about the ugly image.
shaping
It's AP is then most easily positioned to the right such that it hangs to the left of the centre AP used for normal vowels or the tone mark U+1A75. The aim being that it can co-occur horizontally with U+1A75. But that means two glyphs attaching to the same AP. So U+1A6B probably needs its own AP. Sigh.