Yes, the combination is generally safe.
Bell Hammer 7 forms a friction-reducing metal surface film, while AID SEAL works on rubber seals to reduce seepage. Since they act on different targets, they do not chemically interfere.
However, AID SEAL can slightly thicken the oil, so after adding, it's good to monitor:
・Idle sound and engine feel
・Oil level and viscosity change
・Any improvement in seepage
Bell Hammer 7 remains suitable even for high-mileage engines, so you may continue using it along with AID SEAL without issue.