Feature
It would be nice to have echidna add values from state changes and/or emitted events to the corpus.

State changes
A simple example of state changes would be an ERC20 transfer. The new balance(s) might be interesting numbers to find edge cases.

https://etherscan.io/tx/0x483b6382644c114dba9268fa8a45a8c8921666043ea75ae2fc6e09381a5363f2#statechange

Events
An example for events would also be transfering ERC20 or ERC721 tokens. Here you have the value transfered or the id of the NFT.

In my opinion many events hold a treasure trove of interesting numbers. For example:

event ConditionCreated(
	uint256 indexed oracleConditionId,
	uint256 indexed conditionId,
	uint64 timestamp
);
event ConditionResolved(
	uint256 indexed oracleConditionId,
	uint256 indexed conditionId,
	uint64 outcomeWin,
	uint8 state,
	uint256 amountForLp
);

https://github.com/Azuro-protocol/Bug-Bounty/blob/main/contracts/interface/ICore.sol#L37