I understand. You cannot do an "add" or "merge" with another design, i.e., letter then add the frame in the machine.
What I do (I have a 10 needle but sometimes have to use the PE770) is to carefully make sure that both my designs are centered. I always use metric. It takes some time to remember metric but once you know it, it is more accurate for placement than English. Remember that 25mm is approximately 1" so there is a little bit of a clue to help.
So, if I have a monogram that is say 80mm by 100mm, I know that the letter(s) will center because the designs are made that way (most of them). Here is the tip: you need to do what I call a 'discovery' sew. Some people call it a test sew and some call it a sew out. Sew your frame on a scrap of paper and determine what the parameters are for the INSIDE of the frame. You will know the outside because any machine will give that to you. With a little practice, you will be able to do placement with little difficulty.
It would be nice if digitizers could give you the approximate inside parameters. I personally keep a notebook full of information of this sort. Perhaps a 100mm by 120mm frame has the inside of 65mm by 80mm and I would put that into my notebook for reference. It cannot be done simply by math, but you can get an idea of where the ending lines will approximately be.
And, BTW, I often overlap different things including frames. I like to think of them as creating a relationship between the letter and the frame. Why not? If someone were to (no one has) say that they overlap, I would say that the design is an integrated one, they are supposed to overlap.
Those Anna Bovee monograms are just files that you use in the same way as a design. If there is a problem, I cannot see what it might be so let us all know. Incidental, I have a computer dedicated to my embroidery and the other for my personal use. The embroidery PC has Internet access so there are no real issues. If you don't have a PC around, I would bet that you could get a used one cheap - from a reliable source. That may be cheaper than software for your Mac. My grandson has both and I asked him why, he said each had their best uses and shortcomings. Someday soon they will be one in the same. Mac already has one that is compatible with Windows. Tomorrow is always full of surprises.
I sell on Etsy as http://abrideseyeview.etsy.com and you are welcome to review what I personally do. I am currently in the process of adding about 100 fonts and as many embellishments for the hankies as I am able to find.
Play with the inexpensive designs and on your old clothing.
Did you know that Steve Jobs is being heralded as one of histories great inventors? He is being noted among people like Edison and Ben Franklin. Isn't it wonderful that we live in a changing and wondrous time?
Pat, The Avid Embroiderer