Cruiser submarines without treaty limits

Without naval treaties, would cruiser submarines such as X1 enter widespread service?

Navies would keep experimenting, but contemporary technology and operating experience would repeatedly show that the attractive theory performed poorly in practice.

Large gun-armed submarines promised independent cruising power and appealed to several navies before the treaties. Their problem was not simply legal restriction: machinery, handling, vulnerability, and practical employment failed to justify the concept. Removing treaty limits would prolong experimentation rather than guarantee a successful heavy-service type.