After discussing multiple time with users and with Path Tracer developper, it has been decided that 4096 as max samples can be low and some setup could benefit from having more sample than that to reduce noise.
4096 x 4 seems to be a good compromise for the time being.

The best thing would be to have a soft slider that could enable users to go beyond the upper clamped limit. (same way we have for directional light intensity)