There is the initial point where they are just using the product but they aren't yet keeping it. So for example, somebody signed to a SaaS two weeks ago but when you ask to them you can tell they haven't yet decided if they are going to keep it. They are not paying for it, they are still in the evaluation phase, they are still doing many things in parallel, that's not the winning solution. Here you just look at what's the job to be done:
In SaaS, all things being equal, if you can do the all the jobs with the least amount of steps you win. Maybe people are overcomplicating their lives by using multiple products and maybe there is a way to create more simplification. The real switching moment is when they have passed a 90 day period. At that point there is still this consideration to be made:
Sometimes people compromise, that's an opportunity for you to come up with a better value proposition ("Next summit").
All these people are possible early adopters, they come from wherever you find that switching opportunity. It could happen very early in the timeline, this is where rather than getting advanced users who are 90 days into a product and love the product (no switching opportunity) you try to use better marketing and try to go earlier in the funnel and you compete on attention, you try to get people to use your product before your competitors and maybe bring them in your customer factory and influence them to stay.
When you do the interviews you want to get the full story with advanced users. After that you can look back and find where it is that switching opportunity.