Can you add Configurable Items, or maybe even upgrade casings/blocks that can be used to upgrade the machine, like speed, efficiency, or doubling output. It might be difficult, but I think it would add even more power to this already powerful tool. BTW, I love this as a mod pack maker.

This has been suggested a lot - and i'm still thinking on how to implement this without making the JSON machine definitions more cluttered than they already are.

So... i'll leave this open, however this doesn't mean that this will see the light of day.

The upgrade effects could actually be done in the recipies .json, and we only need upgrade slots in the machine if we use blocks in structure, which should just be another ordinary block. In fact, we could make it so we chose a block to be an upgrade block, for instance an external heater from immersive engineering instead of a firebox would allow a boiler to run off of forge energy. These upgrade blocks would then be part of the requirements. Maybe formatted like so
{
"type":"block",
"x" : 0,
"y": 0,
"z" 1,
"registry": "immersiveengineering:metaldevice1@1"
}
Instead of a messy file, you just have an extra recipe file with an extra requirement and an extra block entry in your machine file. It is not designated in the machine file, but just a requirement in the recipe file. What do you think?

Actually, Upgrade Items are already feasible, you just have to set the chance to zero or a very low frequency if you want to have the upgrade item or fluid.

Since there is a way to make upgrade items, I am going to close this.