I wouldn't worry about it at all. I think mgmt started to eval probie on a more regular basis these days. I've received 3 eval. last month alone, and I'm still flying, so I guess i still have a job.
Most CAs do the eval pretty discreetly, so most of the time you wouldn't even know you're being watched, and unless you put the plane and pax at risk, you shouldn't be worried to do the "carpet dance".
I treat every flight as a fed ride to some degree, even though how comfortable and how laid back the flight is, it's just that mentality will prepare you to become a CA one day.