[fidelis]

Yes, John's disciples would ultimately then follow Christ but I wonder why the Gospel has John as the go-to for Christ to be asked to emulate John- unworthy to even loosen the sandals of the Lord- for the Prayer that is so central to Christian worship.

I think John is important for all the reasons you give, but to be precise it is the disciples that ask that Jesus teach them to pray like John taught his disciples, not the Gospel or the Gospel writer holding up John as the standard. The disciples at this point don't get the fact that that Jesus is something far, far, greater than John-- or anyone else. It seems they might have had a little bit of an inferiority complex because John was so highly regarded as a prophet by everyone.

[MurphsLaw]

I don't know the timing...
But I think John's baptism of Jesus is pretty early on too..
I think he was pretty clear that Jesus was numero uno- the One who they were waiting for
That he should decrease in visibility... (Herod took care of that)
just seems he had more prominence than scriptures bear out-
Similar to the lack of the Blessed Virgin activities in the Gosoels...
So the Gospel writer John - years later- starts his Gospel writing with account of John the Baptist... and then then into Jesus... highlighting the Baptist's importance again..
So back to Luke 11...
I wonder if the disciple who asks to teach how to pray like John t he Baptist... could be the Apostle John...
And that maybe he was a disciple of the Baptist-
and possibly familiar with Essene culture as well.

Bergsma has some interesting thoughts on this- nothing concrete-
It could all tie in though.. the Bread and Wine of the Sacrament,