interface order (xen re0 versus rtk0) and kernel modules

["Jeremy C. Reed" <reed%reedmedia.net@localhost>]

Running amd64 5.99.18 under Xen. I was getting many "re0: watchdog 
timeout" and my networking was too slow. So I boot -c and disable re0. 
Now rtk0 is used and it appears to work well.

How can I get this to be the default without recompiling?

Can sborrill's userconf confscript patch be committed? (I have used it 
for several boots to configure userconf automatically.) Then I could 
"disabled re0" automatically.

Since this is a modular system, any way to order or tell modules to use 
rtk0 and not re0? (Even though I don't see any modules named "re" or 
"rtk".)

And where is the documentation on how to tell what modules to boot up 
with? Any configuration or is it just moving modules to/from 
/stand/amd64/5.99.18/modules/ ?