I recall a discussion some time ago suggesting that the lifters (and lifter buckets) and valve springs be replaces at 100,000 km in a LS. It seems that the valve train is the weakest part of an LS so it was considered a ‘gold standard’ (my wording!) to replace the springs and lifters as a precaution at 100,000 km (or was it 100,000 mile?). The trunnion bearings are probably also worthwhile replacing/upgrading too (but, as you have found, they are relatively easy to access and replace later if needed)?
It’s my intention to do the lifters, buckets, and springs at 100,000km. But don’t hold me to that - it can be a case of ‘the road to hell is paved with good intentions’!