So in parent product settings on child products tabs only 50 child products displayed and such value have hardcoded in view.html.php ( administrator\components\com_virtuemart\views\product directory). When i change this variable i able to see all child products but couldn't save parent product properly. Of course i could control child products by clicking on its count in product table, but by example i am not able to change child products ordering there. I think this constant should be moved to virtuemart settings if you are vorry about performance. Anyway 50 products are too few.
Replaced with $maxChilds = VmConfig::get('maxChilds',80);
use the cfg file to set your own value.