These are my personal notes in case I want to repeat the modfication. They are not meant as complete instructions.
Modifying body to heart shaped:
yo at beginning and end of every row. center increases in RS rows (m1r,center stitch, m1l)
Starting chart a per pattern with 129 st.
Adding more mesh rows:
ignoring the start of the outer edge at the beginning of chart c. Adding all mesh rows after row 3. Was aiming for 5, but the decreases only work when an even number of rows is added. So adding 6 (RS)mesh rows with 2/3 increase at the sides.
Starting edge pattern: I had 10 stitches before the first genie
ten stitches mesh with 2/3 increase and k3tog, work repeat sts till end of the row (ends with blue box) ten stitches mesh with sssk and 2/3 increase.
row 9 and 11 decreasing edge stitches by working 2/2 instead of 2/3.
row13 yo,k,boxed stitch
row 15 yo, boxed stitch
row 17 yo, k3
row 19 yo, k2
row 21 yo,k1
row 23 yo, k3tog
row 25: yo,k2tog
row 27: yo,k1, k3tog with bead (instead of the k2tog with bead in the repeat box)

I completely missed the fact that by not starting the edge in row 1 I already added two (RS) rows.So now I´ve added a total of 16 rows to the pattern. Hope it doesn´t destroy the balance.