The last .590 MP camshaft we removed had extreme amounts of wear on one lobe in less than 1,000-miles. When installing a normal, run-of-the-mill hydraulic flat-tappet Summit Racing camshaft into our 318 LA engine, the lifters shipped were absolute junk, we shipped them back for a credit and ordered lifters directly from Lunati. The pushrods I ordered from Comp Cams, same ordeal, had a pushrod ball, literally broken off in the box! We threw those away, and re-used the 40-year old OEM pushrods.
With the 470" low-deck, we went with a Lunati VooDoo Camshaft (which were developed by Harold Brookshire of Ultradyne) that has been excellent (asymmetrical lobes, fast opening - slow closing of the valve) and 3/8", .145 wall pushrods from Steward Performance. This is by far, the best camshaft we've had to date.
Over the last ten years, we've ran the .509 MP, .528 MP, and (TWO) .590 MP camshafts (and a few other Comp Cams). We went with a Lunati VooDoo grind similar to the .528 MP that was substantially better in our turbo build (we actually had that camshaft nitrided). All of these camshafts, other than the last Lunati, had significant wear in under 5,000-miles. The worst camshaft was the Comp XE285HL in terms of lobe wear.
IMHO, it's the lifters at fault. It all comes down to the lifter quality which is sub-standard at best.
Also, take into consideration the break-in process. Don't skimp out on the dedicated break-in oil (AMSOIL) & use a NAPA Gold / WIX oil filter. We even soak the valve springs, pushrods, and rocker arms in Comp Cam valvetrain assembly spray, and generously lube the camshaft & lifters. The most critical part is the initial break-in, this is where you need all the anti-wear additives that dedicated engine break-in oil or conventional oils like VR-1 provide within the first 500-miles. Oil filter needs to be swapped after 15-minutes of runtime, break-in oil can be ran for the first 500-miles. After the break-in period is over, choose a good synthetic oil, from companies like Rotella (15W40) or Mobil 1 (10W40 / 15W50). Do not add additional oil additives.
Engine Masters recently lost a flat-tappet camshaft on the dyno. It can happen to anyone, and is all too common anymore.