What y'all think?

Go for it.

Sure, you might find a better one tomorrow, but it might also take several months. If it had been an 82%IV or something like that, then maybe I would have said you can wait, but 95,6(?) is really
good.

Besides, you will have nine candies left after evolving, will get more from hatching and then there's rare candies, if you were to catch/hatch a 100% (or 98%) one in the future.

I evolved my 95,6%IV one. Never use it, but atleast I've got it in my Pokedex.

If you just want the pokedex entry, go for it. But if you want a battler, you should wait for better moves on Metagross

I don't ever use mine for attacking so I say go for it. It hasn't been very useful except for sticking in a gym for the fun of it.

A hatched Beldum has 1,85% chance of having better IVs. It's entirely possible that you will never get a better one.

There is the consideration of Metagross potentially getting Meteor Mash in a community day later on, but it's unlikely to be in a long while because they don't want to hurt gen 3's longevity.

If you want the dex entry, evolving this one should be relatively safe. Metagross is somewhat useful as the optimal attacker into Gardevoir and Clefable which are common in-between mons in gyms. I frequently use mine for that when fighting gyms.