I came across a discussion here at Puredhamma a few weeks back. I’m not sure if it’s completely relevant to this discussion, but I thought it might have some minor relevance.
“Wrong English translations of Aniccha, Anatta, Sakkaya ditthi… etc”
About 4/5 down the page, there’s a list of contemplation objects based on aniccānupassanā, dukkhānupassanā, anattānupassanā.
In the Petakopadesa post where Lal mentions “There are even more words used to describe anicca in another Tipitaka Commentary. It is not necessary to analyze each of them”.
I’m not sure if Lal was mentioning about this commentary (Patisambhidamagga)? For my own practice, I don’t / haven’t contemplated on all those contemplation objects. I thought it can be of benefit to a Buddha dhamma practitioner to be at least exposed to it.