There are many kinds of block explorers: some are just showing regular blockchain data, as they are handled by full nodes. Some are UTXO-based, and focused on pruned ones. However, when I think about it, I guess we could need another kind of explorer: a signature explorer.

Why it would be needed? Well, there are many questions about z-values. Extracting them from transactions, and signed messages, can be tedious. It is much, much easier, to just hack into the client, and dump signatures in that way, than to write a code from scratch, which would handle FindAndDelete, Segwit, Taproot, Bitcoin Message, and who knows what.

Also, actually signed messages are quite similar, to what is really shown by block explorers anyway. For example: instead of scriptSig, there is a previous output script. Another thing is that if you can see, what is actually signed, then you can better understand different sighashes, SIGHASH_SINGLE bug, s-value grinding, and so on.