I think they will brake as well but dont let what people say effect your work.. A lot of people say things should not be built a certain way or they will not work but you cant let that stop you.. only slightly guide you.
A lot of people for the longest time said a vortex block had to be in a chamber.. I rebelled against that and created the vortex cap.. Also for the longest time it was said that hopups should not be included in BBMGS because they would wear down so quickly. Not only did I ignore that, I built a whole BBMG around a hopup.
So don't let peoples opinions get to you.. It is simple enough to make.. try it out.. who knows maybe it will work.
And if you don't have large compressor dont worry about it.. Aslong as you have an expansion chamber with a large enough valve before the vortex block you should be able to get enough volume.
I would suggest having a 1.5" diameter chamber about 9 inches long, then a 3/4" sprinkler valve going into to vortex block. The pressure will build up in the expansion chamber.. it will increase volume.. that increase in volume will then travel through 3/4" valve and pipe into the vortex block. It would solve the Volume problem without having to worry about an expensive air compressor.
The air comes from the compressor.. it fills up the expansion chamber.. then it is released through the 3/4" sprinkler valve and into the vortex block.
You wouldnt be able to fire constantly... you would fire for a few seconds, wait for it to fill.. then fire again.. you could add a gauge to the chamber so you would know when its full.