Flex board, usage guidelines

Hi!

Is there any information about how to use the flex board?

In the first test I did I selected flex board, but it still printed a raft. It was easy to remove the part, but the remaining of the raft in the flex board are very difficult clean.

Then I tried to print raft-less, but I noticed that the first layer was not sticking everywhere and started creating a ball of plastic on the nozzle, so I cancelled.

I am not sure if the flex board was too far or what. The printer is working perfectly with perf-board, but I am also not sure if the same settings for perf-board are valid or I need to change calibration or anything else.

I have search around, but I cant find any general information about how to use the flexboard, that perhaps is what I need.

How do you use the flex board?