So this is a bit multilayered.
- When supplying the [item=engine-unit] signal to a foundry^, with the config option "Press engines" disabled, it then uses what I assume is a Silly Recipe: "Casting engine unit for the lazy ones" (vgal-lava-engine-unit)
- Unlike Vanilla Galore Continued, there is no option under Space Age Galore config to disable Silly Recipes. I would ask that this be included.

^I like to supply recipes as signals via circuit network, so I can automatically switch them, and Foundry Restructured has a nice Castable Engines ( engine-casting ) recipe which uses molten metal. However, until the issue is fixed on their end, I cannot explicity pick [recipe=engine-casting] from the picker, and JSON editing a blueprint of a constant-combinator will auto-revert a forced [recipe=engine-casting] signal into a [item=engine-unit].

Perhaps a future update down the line for both Space Age Galore and Vanilla Galore could include a comma-seperated text input in the mod config, that allows players to disable/blacklist recipes of their choosing, since both Galores include numerous recipes which some players may wish to fine-tune for their experience. Having a checkbox for each recipe or group might be tedious/bloaty to code.

When supplying the [item=engine-unit] signal to a foundry^, with the config option "Press engines" disabled, it then uses what I assume is a Silly Recipe: "Casting engine unit for the lazy ones" (vgal-lava-engine-unit)

Unfortunately, I can't really provide a fix for this. Currently, when a recipe group isn't enabled (like the silly recipes in this case) the recipe gets hidden, not removed. While you should not be able to see it, the signal can still select it. Making it so instead of hiding the recipe, it never gets added would break this mod and other mods depending on it.

Unlike Vanilla Galore Continued, there is no option under Space Age Galore config to disable Silly Recipes. I would ask that this be included.

The Vanilla Galore options should also work for the Space Age Galore recipes. Can you still see the silly "lava -> engine" recipe when picking recipes while silly recipes are disabled? (If so, that's a bug.)

Perhaps a future update down the line for both Space Age Galore and Vanilla Galore could include a comma-seperated text input in the mod config [...]

Why didn't I think of this...

I'll add it in the next update XD

(Although this will not fix your issue as this will also hide recipes, removing them would break things...)

Thanks for the bugreport/suggestion :D

Yeah, I was trying my hand at the very same thing. I got a blacklist input working, testing it on all three alternate engine recipes. But same result, the recipes are only hidden, not unselectable via signal because item=engine-unit is associated with those recipes. In addition, vgal has a higher recipe group priority than that of Foundry Restructured.

I'm close though. I think there is some final data:extend either in galore-lib or elsewhere that ensures the recipes aren't completely disabled/removed via blacklist, keeping them in a hidden state. Thing is, you'd probably know best where said spot would be, I simply need the blacklist code to run afterwards ^^

Thing is, you'd probably know best where said spot would be

I was there when it was written. Recipes get hidden just before they extend the data table. (In the vgal.lua file found in GaloreLib)

Running the nil blacklisting code should work after all recipes have been added.

(But I disadvice trying to implement a fix on the Galore side of things. It would probably be faster and less crash-prone to fix the Foundry Restructured mod not showing the engine unit recipe in the signal selection. VGAL is not built around nil recipe data, but hidden recipe data.)

I didn't expect you to be implementing it yourself, good luck :D (I will still work on the soft blacklisting input textbox myself of course, the one that just hides instead of nil-ifies.)