I found myself in need of platinum and magmacite and I first came across an extra large, Ultra difficult plasma planet. 13 very small platinum deposits +/-2 of which I mined out all of them getting about 50ish or per deposit, some as low as 4, others in the 70s, or about 550-600 ore after clearing the entire planet over I don't know how long.

I then found a large hell planet and went down for some magmacite, and while doing so, I noticed some oddly coloured surface rocks that turned out to be platinum. Three or four times after clearing a magmacite deposit, I would fly along the coast zapping any platinum rock I spotted and when I left the planet (no where close to striping all the surface rocks) I still had ~1500 ore.

Io compare: The ultra difficult plasma planet has a gravity around 2.85, high heat and high radiation, and more impacting: the horrors/terrors of the deep/from beyond drones that will follow you across the map and are capable of stripping 45k shields in a few bursts, and these drones are everywhere. This is not even mentioning the POIs on the planet and the firepower they can dish out.
While the Hell planet, while no picnic location, has about half the gravity, similar environmental conditions but at least has the occasional flat ground you can land on, and what drone presence there is are your standard types that will not leave their patrol location and pose no real threat to a parked CV with basic shields and a mini-gun or two.

Now, I'm not suggesting that the surface rocks on Hell planets be nurfed, they have their own heightened level of challenge that justifies the reward if someone is willing to fly around scraping 100s of surface rocks. What I am suggesting is the deposit size on one of the more rare and difficult planet types out there, may warrant at least small deposits with maybe a few medium ones sprinkled in.