There is this open pr by moonbeam to bring back background signature verification: https://github.com/paritytech/substrate/pull/10946
I’m personally in favor of this pr (even when I procrastinated hard on it ). I think the current format should be okay, besides that we should add one more change. This was proposed by Pierre some time ago. He said we should attach an unique ID per background validation instance. This way we could have multiple of these instances at the same time.
One important thing that we need to consider before merging this pull request is the impact on the Parachain validation. If we add support for multiple validation instances, we should probably add some cap to prevent spawning infinite of these instances at the same time. Maybe something else I’m missing or other things we should consider.
I’m posting this here mainly to get some feedback/ideas before merging it.