LightSail has (or at least had) a hard limit of 20 instances. They also have a soft limit of 2 instances, after which you must request an upgrade to a higher limit. I had to submit a support request explaining my intended usage. It took a week to get approved.
The stated reason for these limits is to avoid unexpectedly large bills. But I suspect that it's also to prevent crazy-ass strategies for getting around bandwidth costs.
The stated reason for these limits is to avoid unexpectedly large bills. But I suspect that it's also to prevent crazy-ass strategies for getting around bandwidth costs.