Cause of early private submission spike for blob transactions

Determine the primary cause of the high proportion of privately submitted Ethereum type-3 (blob) transactions observed around April 2024 by distinguishing between (i) deliberate private-submission experimentation by blob transaction senders and (ii) incomplete setup or bugs in public mempool logging for the new type-3 transaction format.

Background

The authors use Mempool Dumpster data to measure public mempool visibility of blob (type-3) transactions. In April 2024 they observe up to 20% of blob transactions appearing to be privately submitted, after which private submission drops to nearly zero from May onward.

They highlight uncertainty about whether this early spike reflects genuine private submission behavior by blob posters or artifacts due to mempool loggers not yet fully supporting the new transaction type introduced by EIP-4844.

References

We could not identify the reason for this but presume that it is either blob transaction senders testing out various ways of submitting their transactions or the mempool loggers not being set up properly for the new transaction type yet.

— The Early Days of the Ethereum Blob Fee Market and Lessons Learnt  (2502.12966 - Heimbach et al., 18 Feb 2025) in Appendix A: Private Blob Transactions