Is a heavier scope more susceptible to creep than a lighter scope?!

[Muskett]

Scope creep is a known issue whatever the weight of the scope.
Compared to powder burners springs aren't producing violent recoil forces. They are more rolling and wave like, a shunt. At microlevel then there will be some harmonics going on which might be just enough to break the mount to rail grip.

Heavy scopes such as S&B and Zeiss tactical scopes are rarely found on spring air rifles. However, recent trends have seen larger and larger scopes fitted. A Hawk Sidewinders is getting heavy if not just big. General 80's "Jap" scopes aren't heavy but scope creep can still happen if fitted poorly. The super cheap scopes with integrated mounts used to creep because the mounts were too soft and springy themselves so never gaining adequate grip anyhow.
Shoot to farmyard ranges, which is what springers are really for, then big and heavy scopes is too much. Build a 40m springer and everything goes heavier and big, but the wave forces are dampened just by all that weight. A few extra pounds of combo is enough.

In the past rails for scope mounting were a bit of an after thought and often cut into the receiver (BSA/Webley) which were very shallow. Finding mounts that could grip so shallow was always problematic. This all being a known issue even with light weight scopes HW and FWB built in solutions that mounts could utilise with pins or cross pins. Few rifles today are built without a solution.

A lot comes down to the mounts; not just general quality but compatibility to the rails. Some mount claws are just all wrong for the rails. Questions must be: Are they getting enough grip? Do they have a stop pin or arrestor block? Are rails and mounts complimenting each other by giving a solid grip?

Fitting scopes should be easy, shouldn't it? Well, it's far more involved than just bolting on. I spend considerable time scoping a rifle and matching up all the parts. Wow I've seen some really badly done mounting, and some from gun shops. Quality mounts help but sometimes that isn't enough. Older kit was often difficult, though today there are far more Trade standards being kept to and so making it all so much easier. But even then watch out; Locktite blue can be your friend.