Wow, great to be up! (Especially that I can now see there's no redundancy in the top rope anchor.)
ps. ...and why not sling the post lower (to reduce leverage) and then adjust the length of the slingsuntil the belay carabiners are comfortably over the edge?

...and add another (perhaps several) more anchors for redundancy?

Hey John, thank you for this. This was back in summer on an 'experience day'. I have learnt much better methods to use myself since