when i was small i always thought you have to treat cheques like certs of some kind
then when i was working i asked the admin chick for the lulz can i fold the cheque.
she said sure you can fold it side by side or any origami shape i like
i tried and had been folding since and no problems with receiving the funds or delay in receiving them.
just don't fold untill the magnetic strip is very badly damagaed can already.