I've been looking at HyperDX (ClickStack) and SigNoz, but those indeed are coupled
HyperDX is just a lot better, sure a few papercuts but they got all the important stuff right imo.
Can you share which version of SigNoz did you try or what time frame? We recently made a lot of improvement in how you can host SigNoz including support for Postgres and better docs fro self hosting corretcly - https://signoz.io/docs/collection-agents/get-started/