The thickness of the penetration is most affected by the density of the wood and the length of time under pressure. The harder and heavier the wood is, the closer to finish size you want it. I used to send 3X6X12 blocks of buckeye burl to WSSI and the resin went through and through. I even had big and long blocks of persimmon and maple done. K&G uses a different chamber, and they can't do as large or long a block. What K&G can do that WSSI can't is turn the wood around in a reasonable time frame. I just sent 70# of wood to Ken at K&G.
The primary thing that the wood need before stabilization ids to be DRY. Most state "below 10%", but below 7% is far wiser. Some woods have a convoluted grain, and will warp easily. These need to be 1.5" thick, and may warp or crack even then. Olive is one of those woods. I think it is partly due to the oils in the wood expanding and applying pressure during the heated curing cycle. Redwood burl will tear open all sorts of voids and cracks and warp for the same reason.
I find warp greatly increases as the wood gets below 1" thick. If planning on cutting scales, cut the blocks something like 5X1.5X6". This will still get full penetration, but prevent warp. When back from stabilizing, trim one 5" end square, and then slice into scales like a loaf of bread. This will give unwarped sets of matched scales. I often send wood that will become handle blocks at the same size, and trim four to five handle blocks from it. Another benefit from slicing your scales or blocks from larger pieces of stabilized wood is that the cut surfaces are all flat and parallel, and they are reasonably smooth ... showing the pattern without having to sand every block.
