Weird results when simming trinkets with large secondary stat proc

There are some trinkets (Mirror of Fractured Tomorrows, Inscrutable Quantum Device) that can result in some counter-intuitive recommendations. Specifically, if your top two secondary stats are close to each other, you may sometimes see a higher level version of an item you are already wearing sim as a downgrade.

The most confusing scenario is usually something like this:

• Your current gear has a total of 610 mastery and 609 haste.
• You have a Normal version of an item with haste/crit on it.
• You get the Heroic version as a drop or from your vault - equipping this new item results in more total stats but also changes your highest stat from mastery to haste (since only haste is increasing).
• Using a high secondary proc trinket during Bloodlust always procs the buff based on your highest stat, so with the new item you will get the big trinket haste proc instead of mastery.
• This change in the big trinket buff can result in significantly lower DPS for what otherwise looks like an unambiguous upgrade.

For some specs, one big secondary proc can be significantly more powerful than any other - it's certainly been true for Balance Druids in the past when the mastery proc is really, really good.

In most of these cases, the sim is not wrong or broken, it's that the trinket can significantly affect your DPS even with very small changes in your secondary stats.

In a raid where your group lusts on pull, this result is likely accurate and using the higher level item could be a downgrade in raw DPS. The situation is less clear if lust and trinket usage do not line up (different lust timing, M+, etc).