Forge 1.20.1-47.3.0
SolarCraft 3.3.1.1

Whenever you right-click solarcraft:solar_furnace with an item in either the main hand or offhand, the item will be used as if right-click is being held down, despite being in the furnace UI. For example, if I right click the furnace while there is food in my hand and my player is hungry, the food will be eaten while in the furnace UI.