To my knowledge, (20+ years owning 42 classic Triumphs, overhauling and/or restoring another 20+, being on dozens of Triumph forums & online groups, and dealing with 20+ parts resellers and distributors), I have NEVER heard of cam follower issues along the lines of the horror stories of Norton's infamous "stellite tipped" problems.
As far as I know, as long as you use the proper "R" type when spec'ed, don't mid exhaust and intake, don't mix pre-oiled and oiled style, don't mix used followers with other cams or in any spot other than the one they came out of, you should be just fine.