I’ve been using the following two macros based on all the suggestions posted earlier in this thread. (Thank you all so much btw.)
(Note that these require Talents to be put into Holy Prism and Sacred Shield.)
Macro 1: 255/255 characters used
/castsequence reset=alt/3 Hammer of the Righteous,Judgment,Consecration,Crusader Strike,Holy Wrath,Judgment,Crusader Strike,Sacred Shield,Consecration,Crusader Strike,Judgment,Holy Wrath,Crusader Strike,Holy Prism,Holy Prism
/cast Shield of the Righteous
Macro 2: 255/255 characters used
#show Holy Prism
/castsequence reset=alt/3 Judgment,Hammer of the Righteous,Consecration,Holy Wrath,Crusader Strike,Judgment,Sacred Shield,Crusader Strike,Consecration,Judgment,Crusader Strike,Holy Wrath,Holy Prism,Holy Prism
/cast Shield of the Righteous
Open/pull with Holy Prism (optionally followed by Avenger’s Shield)
Keep spamming 1 until Holy Prism is cast (the icon for Macro 2 should give a visual indicator as to how long is left until that point and whether you’ve already cast it without realizing it), spam 2 when Holy Prism is cast until Holy Prism is cast again. Go back to spamming 1. Toss in Avenger’s Shields whenever it’s up.
I calculated all this out based on a 3 x 9 grid with Crusader Strike (or HotR) prioritized. Apparently there’s only one possible combination of 27 GCDs (40.5 seconds) that includes the maximum possible 9 Crusader Strikes, the maximum 6 Judgments (with max Crusader Strikes), no more than 2 Sacred Shields (as it lasts 30 seconds) with no assumed availability of Avenger’s Shield, with Holy Prism set at 19.5 / 21 second intervals, and no empty gaps.
(The possibility of a 0.5 second gap due to a 19.5 second cooldown for Holy Prism is negated by the fact that an Avenger’s Shield will always be available at least once during this period.)
I doubled up on Holy Prism at the end of both macros to force a soft lockout so that you could flow into the other macro without accidentally disrupting the cycle through a hard lockout.
Since the random proc of the Grand Crusader passive resets the Avenger Shield cooldown and makes it grant Holy Power if fired off within 6 seconds of proc, I didn’t want to use the ability in a static macro and risk the macro locking up if you had already decided to fire the Shield off.
I figured it’s better to just use fire it off whenever it’s available, which tends to be erratic.
TLDR Version: Push 1 until 2’s icon goes gray. Push 2 until 2’s icon goes gray. Repeat.