Factory uses bytes4 to track instanceTypes, this is unjustifiably restrictive

[fulldecent]

The Factory contract wants to track types of contracts. It does this using a bytes4 type. It seems this is inspired from the ERC-165 standard.

The baseline choice should be using a full 32 byte hash. The bytes4 costs more gas to store, retrieve and compare (EVM stores a whole word, Solidity handles truncation) also it has less collision resistance.

As an author of ERC-165 I think bytes4 is a bad choice here.

Recommendation: use a full word hash

References: Definition

erasure-protocol/contracts/modules/Factory.sol

Line 20 in 4a3d98c

bytes4 private _instanceType;

[thegostep]

Change would require redeployment of registries, added for v2