Its tough to judge blends because the short esters have petered out by the time you get the draw. I don't think you can fairly count the short prop ester in this testing at all. Additionally the deconate ester is so heavy that it has less free hormone so you would have to account for that shortage as well.
True, the prop & phenylprop, which makes up 90 mg of each 250 mg inject, would be almost gone by 5 days post-injection, BUT...didn't he say he got bloods done after 10 weeks? If so, the decanoate ester is not disadvantageous when it comes to elevating T levels. Yes, its longer ester results in less active testosterone being released into the bloodstream per mg injected, but this is irrelevant, as the decanoate ester is actually superior to shorter esters when it comes to elevating T levels over the long-term. This is due to its longer half-life leading to a greater build-up in blood levels over time. This is the reason why test cyp/enth always result in higher T levels than prop when tested at 4 weeks out when used at an equal dose...because the longer ester allows for a larger amount of hormone to build-up in the bloodstream. Test decanoate is the same way. Because it is longer than both enth & cyp, it will result in a higher peak blood level than either of them when used at equivalent doses (assuming it is used long enough to allow the blood level to reach its peak, which in this case was more than long enough).
Since testing was done at 10 weeks out, blood levels would already be at their peak when using decanoate. Although I could not say exactly, 100 mg of test undecanoate, when tested at peak blood levels, would probably provide a blood level equivalent to about 115-120 mg of test cyp or enth, so it is certainly better at elevating and sustaining blood levels with long-term use.
Sust also contains 60 mg of the isocaproate ester, which is almost as long as the enth ester. In total, each 250 mg injection supplies 160 mg of long-estered test (100 mg undecanoate & 60 mg isocaproate). In reality, an equal combination of decanoate and isocaproate is probably really damn close to proving peak blood levels similar to test cyp, as the one ester is slightly longer than cyp and the other slightly shorter. However, because more undecanoate is used than isocaproate (almost twice as much), the 100 mg Decano & 60 mg Iso found in Sust should result in slightly higher blood levels than straight test cyp when used at the same dose (160 mg).
In other words, 100 undec + 60 mg Iso is superior to 160 mg test cyp for maximizing T concentrations once peak blood levels are reached.
So, if he was using 1,000 mg of Sust per week, his total longe ester dose would be 640 mg (360 decan + 240 mg iso). Although the prop & phenyl prop, which equals out to 360 mg per week combined, would be almost gone at 5 days post-injection, it would not be completely gone--some would still be hanging around. Therefore, at least some of it needs to be included in the equation. All in all, the OP should have experienced a blood level similar to what is experienced when using at least 700 mg of test cyp at 5 days post-inject.
700 mg of long-esterd gear weekly, with the majority of it coming from the decanoate ester, should result in some pretty damn high blood levels after 10 weeks of regular use. In other words, thety should definitely be higher than what the test results indicated--considerably. however, I suppose it is possible, especially when dealing with UG's, that the ester ratio was not accurate. I have encountered gear before that was supposed to be Sust, but contained almost all prop. Needless to say, when I got blood work done at 7 days post-inject, my blood levels were shit--barely elevated. I was discreetly informed that this particular batch may have been screwed up and contained much more prop than it was supposed to, so I re-tested it a few weeks later at 2 days post-injection and my levels were through the roof, indicating that it did indeed contain much more prop than the label stated.
I am not saying this is the case here, but you never know with UGL's--weirder stuff has happened.