1. Different buildings provide different fuel recovery bonuses. Your bonus will be affected if guardian status has been modified by the R4/R5 members.
2. Losing control of the building you are assigned as a guardian will remove the fuel recovery bonus provided by it.
3. Adjusting the guardianship yourself will affect your fuel recovery bonus.
4. Leaving the battlefield will revoke your guardianship to any building, and you will not regain the Guardian bonus after rejoining the battlefield.