If you give the user time to get through all of the integrations/setup steps, you should be even more confident in your ability to convert them as they're invested at that point.
If you're worried about the 'load' of a user on your SaaS, then you have bigger issues to solve because the unit economics of having a low usage/free tier user should be essentially free. If a user does require a lot of human touch/support during their trial, then I feel like you handle that manually on a case by case basis. It's likely going to be rare and you can decide how to handle (eg. talk to them about paying for support / moving to a paid plan / etc). I tend to believe you're missing out on the learning and feedback loop from these types of users even if you perceive them as unprofitable or what have you.