Qult back with appliqued pictures
 

I want to put a few appliqued squares on the backing for my quilt. Does this make it harder to quilt with a longarm? I send mine to a long-armer who uses a computer for quilting. I am just going to cut the squares out, scatter them across the back and zigzag around them allowing to fray a bit. Will this be ok with the quilting process? Thanks for any advice.

As a long armer, I don't see a problem unless they are fused--depending on the fusible used it can sometimes cause the needle to stick and slow down. On the back that would be a particular problem. Of course, since they would not be visible, it means that the quilting would just go over them.

You'd be best to speak directly with your longarmer.
Each have different skills and abilities to deal with unique things that we do.
Some are more capable than others!
Too, their machines and set ups are different.

By asking up front, you might find out that your LA'er can do it if you do it this way,
whereas, the other way, they cannot. And you might even get some added hints for it to work!

It's always best to ask early, than to be disappointed after the fact.