Bought my first own enlarger (Durst M609) yesterday. Not sure if turns up to be a good deal but expensive it was not so no big losses expected. I did do some background check before buying it and M609 was widely regarded as good enlarger for B&W work. I have some questions about M609 though:

What type of lens boards does it use? Are they same as the modern Durst lens boards?

It comes with a 6x9cm glass negative holder. Can that be used for enlarging smaller negatives like 6x6cm?

If these sound like beginner questions then you are right. I have used couple of enlargers earlier but I am still a beginner when it comes to darkroom work.