Grand Principle of Harmonious Combination

Question: As I recall, there's a Taiyi boon which lets you pick a second purview for any boon to fall under. If you had one primary purview, couldn't you, in theory, just change any level one boon to your chosen purview and cherry-pick level 1 boons willy-nilly with no drawbacks? Would you let your players do this so they had a huge 'toolbox' of level one boons?

You're thinking of Five-Cycle Conjunction, the level three Taiyi boon; it allows Scions to choose APP boons and designate them as belonging to a second APP as well, so that a Fertility boon is also a Frost boon or a Guardian boon is also a Justice boon. The boon's main purpose is to defend against the level two Taiyi power, Yin-Yang Destruction, which allows Scions to simply negate the effects of normal APP boons; if a boon is part of two different APPs, it can't be countered that way.

But no, Scions can't pick up a bunch of low-level boons and end up being able to circumvent the need for relics or get themselves a massive buff to the total number of boons they have in a purview. Five-Cycle Conjunction is limited by a Scion's Taiyi boons; they can only choose one other APP boon to become double-purviewed for each new dot of Taiyi they gain afterward, so they're only going to get a total of eight over the entire life of their character's development and will only be gaining one every time they go up in Legend and can buy a new dot of their PSP. I suppose they could waste them all on level one boons for a quick bonus at low levels, but they'll be unable to use that limited number for anything useful later on if they do.

It's a very academic question for us, since it's extremely likely that very little of the current Taiyi purview is going to remain when we do our Celestial Bureaucracy overhaul; I can almost guarantee that this boon'll be gone when we rewrite the purview. But until then, it can give you bonuses and allow Scions to use a bunch of boons without relics, but it's definitely not unlimited, and choosing boons for quantity instead of utility will probably just bite the slippery Scion who tries it in the ass.