Clarification on Ultimatum stacking.

Hello.

I am confused on how stacking multiple copies of "area contains an ultimatum encounter" works.

The map craft can force an instance a random ultimatum on the map, but so does the sextant. Ultimatum scarabs also force it with some giving monster experience and rewards starting at a higher tier, which I assume stacks with the atlas passive doing the same thing.

What happens if you put a map in the map device with the sextant mod for ultimatum, craft it, and use any ultimatum scarab?

I have tried using the map craft + sextant and the craft consumed both chaos and a sextant use, but the map only had one encounter. Does this just take the chaos or does it actually have a benefit? I want to assume that it does nothing, but since the line on scarabs say that you start at a higher reward level or are considered a round higher, that stacking multiple instances of ultimatum encounters does the same.

Does anyone know if stacking does anything? Or am I better off just using a sextant to force it for my mapping?

Some encounters are limited to one per instance - Ultimatum is one of these. Others include Blight, Harvest, and Expedition. Trying to force more on will consume the resource but fail.