Perfect! I was also running the napkin math on best HSP itemization. Technically the Bracelets of Royal Redemption inconjuction with T2 helm/gloves/belt have slightly more HSP (16) but you lose a crap ton of MP5 (-17); is this one of those corner cases where you just want to get the "best bang for your buck"?
Friend showed me this but it seems for pure throughput it is probably better to go Royal Redemption Bracers + t2 boots over t2 bracers + boots of pure thought.
Yes, technically Royal Redemption are better from a pure throughput perspective but that's not what BiS technically is. Or rather it would be if the lens you were viewing BiS through was specifically throughput in a situation with no mana constraints. There are all manner of margin calls I make when I consider BiS but, for general use, I adhere to this gear list when I can. Not everyone plays under the same environmental factors so the weights are geared around 3 to 5 minutes of combat. For individual boss encounters, not trash which is the majority of the instance and most significant aspect of a raid, you may want to go full throughput when mana constraints are irrelevant.
Also the Helm, Gloves, Belt sacrifices CAC, DGC or Don Rig's. If you wanted to go Royal Redemption you should run Gloves, Belt, Boots. Balancing T2 3pc among all possible loot permutations makes it very complicated for the playerbase as well. As @Kenny pointed out in the snap he linked, that reduces the +heal gain to 9 and a loss of 6MP5. Only for extremely short encounters would I make that trade and I definitely wouldn't build my entire purchase power around it. If you can pick up Royal Redemption for the use cases it is ideal in without taking it away from a player for whom it would be of greater impact, or if BoPT are extremely rare for your raid, sure, more power to you. IMO the Royal Redemption gear set is overall slightly inferior to the BoPT gear set but still completely viable.
@Turm-Runescape This isn't true, T2.5 will overtake T2 concretely typically after ~25 seconds assuming balanced gear between both sets. Actually slightly faster which is related to the point you brought up about Crit. The value of T2.5 is not sniping. I really disagree with the entire concept of sniping. Sniping is only sniping if you are purposefully using a lower cast time spell and OOMing yourself in the process to accomplish cosmetically higher healing in relation to your healing roster. Basically expending your mana needlessly to push out other healers from the available damage pool. This also assumes the benefit of casting the faster heal is minimal; which, the majority of the time, it isn't. There is nearly always a strong benefit to getting healing out more promptly. That is why I argue it is very hard to actually "snipe" healing in the way people commonly gripe about it. However, that is not what T2.5 is at all and it would be extremely hard to use it as a "snipe set" if that were a thing. If you were to argue it is the entire premise there is that "Haste is for sniping" which is not true.
But you are correct about the strengths of T2 in an environment with fewer healers or less competition and in regards to the ease of a T2.5 Shaman "slotting" their heal into available health deficits. In reality you want some Shaman on T2.5 and the remainder on T2 outside of strat specific requirements as they provide two slightly different styles of CH. The real reason T2.5 isn't straight up better in every situation is because of the manner in which damage is done in Classic. Most encounters have mechanics which apply damage over a brief duration followed by downtime until the next damaging mechanic. This means that there can be significant stoppage and startage of casting and, during the periods of damage, only a few GCDs are capable of being expended before the raid is stable. A proactive healer precasting into this kind of damage drastically reduces the benefit of T2.5 as the entire benefit of the set can be lost in comparison to T2 -assuming both sets are being worn by players of equal skill. If a damaging mechanic only has 3 to 5 GCDs worth of casts before the raid is capped before a stoppage period occurs it can be challenging for the T2.5 Shaman to get the full use out of their set. However, it can definitely offset a reactive healer's ability to respond to damage and this, in practice, is what most people perceive as the actual benefit of the set despite it being only an incidental benefit. Two reactive healers addressing the same 3 to 5 GCDs worth of damage before the raid is capped and a break in casting occurs finds the T2.5 set is at a distinct advantage.