I also have a Bernina 830LE. I've done lots of FSL. I find Vilene or Aquamesh works best. It's more like fabric & doesn't rip apart when stitching out the designs. I gave up trying to use film in the hoop & only use the thin stuff on top when needed. Decide what size hoop you will use the most doing FSL & by the size to fit it. Less waste.
I often load several designs in the jumbo hoop to save on stabilizer use. The downside when doing FSL is you need to entirely stitch one design at a time or the Water Soluble Stabilizer can shift throwing the other designs off. Example...you want to stitch out say 3 angels. They are all white. You stitch out the outline, then the wings, skirt, head, etc. Once you go back & forth, to each of the 3 designs, in your hoop, the stabilizer pulled a tiny bit & now your 2nd & 3rd angles wings, skirt, head, etc., do not meet where they are supposed to. I found this out the hard way & wasted a entire hoop full of designs, thread, stabilizer & time.
With the left over scraps of Vilene or Aquamesh you can carefully moisten the edges (barely moisten) & paste them together to make a piece big enough to hoop. Do it on a surface it will peel off easily. Some use metal baking sheets. Let it dry totally before using. I slow my machine down, until the outline stitches have gone over all the patched seams, so it will all hold together well during the rest of the rest of the stitch out process.
Hope this works for you. I love doing FSL. I have one of the Angel Tree Topper designs from Embroidery Library I'll be doing soon. I'm also planning to make some of their 3D butterflies as gifts too.