Art:  I have 85 hours on a LIV similar to your's (unpressurized) and am surprised to hear you have experienced the "typical" hesitation when switching tanks--I had come to believe this is caused by pressurization and maybe a leaky fuel selector valve.  To answer your specific question:  I have not experienced similar and have switched tanks both above 10k with low boost on and below 10k with low boost off.  I do not have loops in my fuel lines at the wing/fuse junction because I brought them in via the aft stub spar.  They are also 1/2 inch, the boost pump in on the floor just behind the NG tunnel and the rest is pretty standard.

I will be on my toes as I approach 110 hours, or venture near Texas.

paul