You can largely see the choices that NOs have made regarding relays either via https://fees-monitoring.lido.fi/ (and there’s additional work to be done here for sure in terms of giving more insights into historical / overall use) or eg via https://www.rated.network/o/Lido?network=mainnet&view=pool . Although there is a “bias” in the data here which basically shows “relays used” instead of “relays configured” (since it looks at blocks which actually landed), I think over time that’s kind of all that matters (e.g. “if you configure a relay that never lands a block, is it really a relay” kinda thing =D).
The thing that will be more difficult to expose is usage of min-bid, and I think a survey will certainly help in that regard. The question of DVT and relays becomes a bit more difficult, because how each different DVT infra solution approaches block proposal duties will determine to what extent the cluster participants need to be fully / somewhat / not aligned in terms of things like MEV Boost and relay configuration.
There’s definitely work that needs to be done even before mainnet in terms of understanding the limitations and possible resulting constraint requirements that might result from different DVT-driven operator configurations. The scope of these questions/problems – and hopefully some early answers – should be born out of the next round of DVT testing https://twitter.com/LidoFinance/status/1621503397139742721