OK gotcha yes that makes sense. Thanks for the help much appreciatedOkay. On the far left side where the stand is touching the floor you don't need a shim there.
What we are trying to suggest is that between the shims you have already put in, it is best to add more shims between them. Where your stand is mostly likely to bow is the unsupported area between the shims. If you do add these shims you don't want to drive them in very hard. They are just there to take up the space between the stand and the floor. They just need to be tight enough that they can't move, and then cut/break them off even with the stand so they don't stick out.
Hopefully I have explained that in some way that makes sense.
ETA- I also should've mentioned that you should add them between the left (where the stand touches the floor, and the center shim. Just go far enough left that you can easily get the shim between the stand and floor, and again dont drive them in too hard, you don't want to drive them hard enough to lift up on the stand.