Should builder block submissions override previous one by same builder even if less profitable?

[metachris]

See also: at what level should cancellations be allowed, if at all? #113

[metachris]

Perhaps this feature could be opt-in (i.e. with a request header), it might be a little risky for less sophisticated builders to accidentally overwrite their better blocks before 🤔

Implementation-wise it could look like this:

• for each builder, keep the latest bid around in a cache (redis / db)
• once a builder submits a new bid, replace the latest bid in the cache and prepare the current best-bid to be delivered on getHeader requests