Integrating headphone system

Using 1 Line Out would I believe,mute the speakers as the power amplifier would be fed from a different output...Use the Tape Out & HPA as volume control to cans...
 That said,using 2 preamplifiers seems like a complicated & unbalanced system...

Yes, Tape out or Fixed output is always the best way to connect a headphone Amp. My integrated has a headphone Amp built in but I prefer my Quicksilver HP Amp.  

I use Fixed out to the Amp with great results.   I just turn the volume all the way down on the Integrated to mute the speakers.  

Tape out works best for me. I had a balanced tape out with my X1 and I have balanced tape out with my XP-32. I don’t think that the XP-22 has balanced tape out but you could use single end rca tape out for HPA.

Thanks for confirming. Initially I thought I could use output 5 that is configured for HT bypass. I’ll experiment with the tape out. 
 

Yeah. The second preamp for phono isn’t ideal. I’m doing some research on a proper phono pre.  
 

I use speakers taps out of my 2CH amp for HP listening. Works really well. No need for separate HP amp.

https://fogcityaudio.com/products/adaptor-cable-speaker-banana-plugs-to-female-4-pin-xlr

I would be very careful using speaker taps. It does work well for certain difficult headphones. Like the HifiMan Susvara and older HE6 models. They needs tons of power and so speaker taps are a good way of getting them there. For most other headphones of normal sensitivity I wouldn't recommend it though. I almost ruined a pair of expensive Focal Utopias that way!

Have you looked into the Pass Labs HPA1? It's a really great headphone amp.