Its your call. If you do not already have SMC S, and you think you have a potential of 100 plus an additional combined 60percent, then that extra 350 or so per month for SMC S is probably worth it.
I do not buy into the theory that applying for an increase can result in a decrease, as there isnt any real evidence to support that theory except “uncle charlie” evidence. That is, my “uncle charlie” died wearing blue clothes, so dont wear blue clothes or you will die, too.
The color of jeans you wear, or whether or not you watch “MASH” reruns, or whether or not you apply for an increase are independent of whether or not you will be reduced in disability rating. The relevant criteria is, “did your condition improve, and is this improvement “sustained” (long lasting vs just a short term improvement).
If your disabilities did not improve, then you have little to worry about a reduction.
There is a more important reason for an increase other than just SMC S, however.
Think about someone other than yourself..your wife.
She can get DIC if you die:
1. Of a service connected condition OR
2. Die of any reason after you have been service connected 100 percent for 10 years.
So, lets say you have not been SC for 10 years, but have HEP C, and its killing your liver, but you are only sc for PTSD at 100 percent. This might be a good time to apply for hep c, so that your wife can get DIC, as you are unlikely to die from PTSD, but Hep C is a killer, unless you respond well to the new hep c drug.
If the DIC is irrelevant, I think its best to leave it alone, not because you will be reduced for applying for more benefits, but because you are giving your military brothers who are injured a chance, because a rating specialist wont be working on your claim, that wont benefit your or your family, and, instead, will be working on a claim where the difference could mean that Vet is not homeless.
100 percent Vets are rarely homeless as these benefits should be enough to provide a roof over your head. (That is, of course, assuming you are not spending your entire check on cocaine, heroine, and alcohol)