I had a long response typed out, but the kitten just deleted it!

From what I read today (see the Bontrager thread), we actually do put significant weight on the pubic rami- sometimes more there than on the ischial tuberosities. Especially in the drops, you should be able to tip the pelvis forward onto the rami and be supported. My current saddle unfortunately also tries to support a lot at the pubic symphysis (and thus girly bits), so I'm still hunting for one that has the right shape up front. I'm trying the Lithia tonight on the trainer and have a SMP TRK on order, but if those don't work, maybe I'll try out the new Bontrager.

For those non-anatomists: