Consider one long tapered elastomeric bearing. The angle of the taper will be great enough that the centrifugal force can be supported over the length of the bearing. The angle of the taper will be small enough that the radial forces, near each end can support the moments from the blade..

The shims could be cut from a long tapered composite tube ~ maybe from braided carbon.

Would the additional elastomer add too much resistance to the pitch bearing? Alternatively, would the fact that there are only two 'open ends, instead of four, result in only two locations for stiffer elastomer material? (softer material in the middle)