I made some recipes with inverted sugar and it worked very good. For inverted sugar:
240 ml water
1/8 tea spoon of lemon acid
You have to boil it while mixing on high heat, then let it simmer for 20 minutes on medium heat. The temperature goes up to 114?C. You have to cool it down to room temperature and then store it in the refregerator.
I made pistachio marzipan for Chocolate-Pistachio Marzipan Spirals, Food Processor Poured Fondant and Quintessential Marzipan with inverted sugar instead of corn syrup and it worked.
Here are some pictures…