I've tried this:

	"components": {
		"R": {
			"type": "compactcrafting:block",
			"block": "minecraft:redstone"
		},
		"I": {
			"type":"compactcrafting:block",
			"block": "minecraft:iron_block"
		}
		},

And it doesn't work because of the redstone.
Does there need to be something else than "compactcrafting:block"?
Please help.

I believe you want redstone_wire, not redstone there. redstone is the item form. You can always use F3 mode to check names and property values.

(FYI - There is an extra properties group that you can add for specific whitelisting of properties. There's an example under the tests for the block component.

Closing this as stale for lack of response; please comment if this is still an issue. Thanks!