MCreator issue tracker has been migrated to GitHub.
Existing tickets have been migrated to GitHub. Please open new tickets on the GitHub tracker instead. If you do not have a GitHub account, all feature requests and bug reports from forums are still considered and checked by the maintainers.
We will add this in the future updates. For now, you can use TileEntityFurnace.getItemBurnTime(itemstack) for this in custom code.