Hi Nick,
can only talk about the Zlin 142. Made my aerobatic endorsement on this aircraft in June 2007 in the czech republic. Great aircraft, the hottest plane I ever flow. Big fun.
But these aircraft needed an airframe overhole every 600h. There were some problems with the wing spar, leading to an fatal accident in the early 90.
Since then the manufacter hat lots of problems with the (western) authorities.
For some reason the manufacter did not react. Someone told me, they had financial problems, don't know.
At the time of my aerobatic course, EASA reacted. Aerobatic was only allowed on aircraft, not more then 180h since overhole. Aircraft must have been fittet with a black box, recording g's. Envelope was limited to +5g.
Only talking about the 142, but I think the 242 has the same airframe.
My information is several years old, thing may have changed.
But before buying one, inform yourself about the overhole and wing-spar-issue. It could cost you a lot of money.
If the 242 has a modified wing spar and airframe- time is not limited, buy it.
Joe