Flat tappet cams can survive providing they are broke in properly, they do not have excessive spring pressure.....faster ramps and higher rpm and turbo demands need more spring.
A high quality oil is used, brad penn and VR1 are good oils, zddp additives help. I would not run a cheap oil or synthetic with a flat tappet. IMO
There are the oem GM lifters with the hard cap on the lifter face that are the best and everything else wishes they were as good.
The Turbo Regal engine block has an unusual flaw in its design...the #3 exhaust lifter bore offset is different than the rest and this can interfere with lifter rotation unless a reverse taper is called out for that lobe when the cam is made.
It used to be fairly common for our engines to lose the #3 exhaust lobe.
Now I like and recommend using a roller cam when your wallet allows it, But they are far from foolproof and there is plenty that go wrong with a roller cam set up. Link bars loose and noisy, wheels chew through improperly hardened
bodies, needle bearings fail, cam lobe surface chips off, thrust bearing and cam retainer plate issues to name a few.
Bottom line is the camshaft is a highly stressed component in your engine and there is no guarantee that either type will be trouble free. Do your research and make sure you understand the pros and cons of each set up.