The Czech Supreme Court ("Court") approached this issue in a recent decision, where the arbitration clause was contained in an exchange of emails without a qualified electronic signature (for the definition see, e.g., eIDAS Regulation). The issue before the Court was not an easy one, as in its case-law regarding "domestic" matters the Court interpreted the writing requirement under the Czech Civil Code as requiring a qualified electronic signature (see, e.g., this decision).
The Court had to decide, whether this interpretation applies also to the Convention.