I know there is a MarketplaceService:GetDeveloperProductsAsync() but that’s only for the current game, I want to get other games’ developer products.
There is no current way of doing this as far as I am aware.
I can second this. You cannot view other games’ dev products with any publicly accessible API.
I can third this. You shouldn’t have a need to see another game’s developer products because they can’t be used by places outside of the game in the first place.