The EU rules are quite clear. It must be clear prior to booking a flight how much it will cost. Adding EUR 40 for printing a boarding pass is insane and a violation of these rules.
FR was quite often now in court about these (and other) rules and they always lost. When do they learn? Never.
The alternative FR pointed out or removing any check-in machines won't help either, because the record of booking in the booking machine of FR is prove enough for a flight. In theory, you could just go to the airport without any ticket, show your passport for ID and FR has to issue the ticket and boarding pass - without any extra handling, printing, ... fee.
I don't fly them - even for free. There are so many hidden and illegal fees involved that you never know how much you will pay in the end.
BTW: I don't have the reference, but FR stated one day that the EU law for customer rights do not apply to them, because it is obvious that for that little money charged FR will not have the ability to pay their customers a hotel night for canceled flights.
