I've lapped valves and re-cut valve seats on Honda engines for over 40 years without issue! What I wouldn't do, is reface the valves themselves. If pitting on the valves is minor and can be lapped out by hand in under 10 minute per valve then I'm ok with that. If the pitting is severe or needs more than 10 minutes of lapping by hand, then I replace the valves. Cutting seats is just fine, there's no extra coatings or anything on them, your limit with a shimmed engine is available shim sizes.