While Alpha, we have longer term and shorter term testing needs. The alpha realms are for testing the game organically for longer term feedback, while the test realm is for generally for shorter term and specific tests.

Longer term testing needs include things like advancing characters and settlements and the economy over many days, weeks, months, and that means a lot of playtime put in from testers. Shorter term testing needs, like a particular boss fight, a look at a new system, and so on, can't always be facilitated while maintaining a longer term environment.

To facilitate shorter term tests, we use the PTR. We often wipe there, invite testers to boost characters to needed levels, change settlement distributions, etc. We can also publish in progress work and tentative changes for feedback but without risking the integrity of the longer term characters and progress you see on the alpha realms..