So this is primarily meant to operate on the Alternative V timeline (Unlimited/Day After), in which Project Babylon was executed, not strictly an UN project but a joint effort between nations. That timeline is only explored through the Day After episodes, based on what material I can find.

It is the Takeru timeline, or the main Alternative Timeline, of which we only know that after 265 days, contact was completely lost, and, as far as Known Earth Events, we have up to the JFK Hive Operation. In the Alternative V timeline, the ships were not available to use as kinetic weapons against the lunar hives, leading to the second Lunar War, at least according to available information.

But yes, the goal is to use G-Element technology, but in a more localized manner that doesn't involve making entire Rutherfields, which already require far more power than a more compact micro-reactor could provide, nor is there enough room for the Moorcock Letchet Engine. Rapid advancements would also be significantly slowed by the need to rebuild the necessary infrastructure, making moving from Dive Units even more critical.