T8r - I'm noticing something. I ran your numbers 20+10+10 and according to the Combined Ratings Table, here, at Hadit.com, you should be receiving 40%. According to the chart the combination equals 35%, which always rounds up, which would make it 40%. You may want to check the VA's chart, to confirm.
pr
PS - I just checked 38 CFR 4.25, at the GPO, and I am correct. You should be being paid at the 40% rate. If you are not being paid at the 40% rate, presently, then you should contact your VARO, explain the error, and have the amount corrected to whenever you were awarded 20+10+10 combined percentages.
And you owe me a cup of coffee, sometime! jmo
pr