So you want to spam Rank 1 Renew just so you can proc the trinket to get 15 seconds of the ''5 second rule'', while keeping your self out of the ''5 second rule'' by spamming the renew? The trinket does not give any other benefit other than what you would get if you did not spam renew and just waited 5 seconds to get the same effect as the trinket. Or am I missing something here?
If you mean to instantly spam R1 Renew right after a heal, this can work but you are like punishing yourself for +27 increased mana EVERY heal you cast + 1.5 seconds extra downtime by the global cooldown. The 2% is way too low to do this cause you will lose more mana then gain IMO and also will fuck your heal spamming/precasting.