Compound adjectives functioning as adverbs modifying other adjectives; is it possible and grammatical?

Solution 1:

All your examples are correct. These are adverbs rather than adjectives. Specifically, they're participial adjectives that have been turned into adverbs using the "ly" suffix. They also all follow a pattern where the noun added to turn them into a compound is the noun that would be the direct object of the verb. (e.g., soul-crushingly bad = bad enough to crush souls). There are other examples that follow the same pattern (e.g., "breathtakingly beautiful").

The "add -ly and use it as an adverb of manner" construction doesn't seem to work on all compound participial adjectives. There's no such adverb as "hard-workingly" or "time-consumingly," for example, even though time-consumingly fits the same pattern as soul-crushingly).