Writing is a powerful tool for thinking, so any time you need to make architectural decisions, an ADR is a good tool for thinking and discussion. Plus, when someone asks you in the future why you did something, you have documentation you can point to.
Great article -- I'm a fan of ADRs as well -- have been using them to think through various decision points in the SIOT project: https://docs.simpleiot.org/docs/adr/index.html
Writing is a powerful tool for thinking, so any time you need to make architectural decisions, an ADR is a good tool for thinking and discussion. Plus, when someone asks you in the future why you did something, you have documentation you can point to.