I modeled this as my contribution to spread the word during Autism Awareness Month.
My youngest son is on the spectrum and together we are learning what it means to live a life on the spectrum.
And as you can see he approves of the puzzle.
To get the letters on the back of the heart, print those only first, then print the heart on top of them without removing them from the bed.
Even with auto and mesh leveling they are only 1 layer high and should not interfere with the process.
Or you can print the base without the letters they are cut out and will show anyway.