Hardboard over 5mm ply

I was wondering if its a good idea to put hardboard over 5mm ply. I like the smooth white finish and need it to cover up a few small bumps I created when installing the inside roof skin.
While installing the inside skin, I heard some cracking of the 5mm ply and saw some crack lines on the outside. Once I had a few spars of screws in, the cracking stopped, but I was left with some small bumps/ bubbles.
I have it all glued nicely, but wondering if the cracking was a concern.
Thanks
While installing the inside skin, I heard some cracking of the 5mm ply and saw some crack lines on the outside. Once I had a few spars of screws in, the cracking stopped, but I was left with some small bumps/ bubbles.
I have it all glued nicely, but wondering if the cracking was a concern.
Thanks