Is it possible to specify a specific server name/server id for dispatcher to use to send pings with (and in outgoing requests)

It seems I can't (or haven't noticed in the docs) an event route I could use to set the xavp, as tm:local-request happens to late to use there. As an aside why isn't there a "last chance before send" event route?

This is probably a feature request more than a bug, as the ideal solution from my point of view would be an additional dispatcher attrs value to be able to set it per destination in the underlying dispatcher data

Judging by the output from tls module dbg the tls xavps are checked, before the ping is sent..

I've had a cursery glance at dispatch.c and it seems easy enough to add an extra attr parameter but I'm ata loss as to how I would preset the server name/id xavp... (I'm no c dev, but can Google quick enough to follow along mostly, and happy to fiddle away if anyone can be kind enough to give me some pointers in the right direction)