Chia has started a full implementation of BLS signatures:
BLS (short for Boney-Lynn-Shacham) is a newer signature scheme based on elliptic curve pairings that has many attractive features. In particular for Grin, BLS signatures can be aggregated non-interactively, including with different messages. This would allow kernels aggregation, perhaps not in every single case (kernels can still be useful for scriptless scripts) but in the great majority of cases.
Note that Ethereum is also looking at BLS:
Also relevant, a common pitfall of BLS implementations: