i always use the block, and insert the skewers while everything is sitting on the plate, so the pieces are supported by the plate when i'm jamming in the skewer.
my sister, who is a little crazy, will score the feta block and BEFORE CUTTING pokes a hole with the skewer in the center of each 'scored' block. she claims if you pre-hole the feta before you cut it, it doesn't fall apart.
i don't know, i haven't had issues with blocks and plate-jamming the skewers.
As long as EVERYONE LIKED IT, who cares if it was on a skewer or in a bowl!!! they'll never know you tried to skewer in the first place, right?