Per the January 2023 plenary session, we should remove support for InstallErrorCause from the SuppressedError constructor. A SuppressedError already has two conceptual causes: the suppressing error and the suppressed error. In the case of a using declaration, a SuppressedError is only thrown when both conceptual causes are present, thus neither is definitively the "cause" of the SuppressedError.
InstallErrorCause introduces a third conceptual cause, which is an unnnecessary overcomplication. As a result, the consensus agreement is to remove support for InstallErrorCause in this case.