Thank you! (But why do you "know" you "can't do" the FSL lace heart? I can share some tips with you.)
Please share but I was very discouraged last time I tried. This one has too many stitches for my machine to handle and it is such a beautiful heart.
Attach some light weight, rubbery shelf liner to your hoop (https://www.criswell-emb.com/albu...). Use 2 pieces of fiberous WSS, one laid at 45 degree angle over the other. Make sure these are smooth. Tighten the screw on your hoop prior to hooping the WSS as adjusting the screw after hooping can be a major cause of distortion and thus failure of your FSL project. Use the smallest hoop possible and only stitch one FSL design at a time.
Hope these hints are helpful to you!