While the ticket descriptors are not in scope, the code calling them is. NFTLoanTicket.tokenURI(), which is in scope, ends up calling descriptor code which casts the asset to IERC20Metadata. This interface is separate from IERC20 because EIP-20 does not require those functions to exist. If a valid ERC20 token does not implement this interface, casting it and attempting to call non-existant functions will cause the code to revert, which will cause tokenURI() to revert.
PopulateSVGParams.sol#L65
PopulateSVGParams.sol#L69
PopulateSVGParams.sol#L83
Use safeDecimals() etc
