You can short focus your primary on the stage 1 divergence MM diodes, that is NDG7475, NDB7875, M-140, PLPM450B and the old 1 watt pretty well but you are cutting the full potential of 10X short, the higher divergence such as NUBM44 and NUBM08 are hard to get more than half the power out in my experience, I did focus a what I call ( stage 2 ) divergence NUBM07 to 7 feet and got a rectangle ( Tight burning one ) at 15 feet with the Jet 10X but far field you can see the beam bouncing of the inner walls of the BE.
When you put a diverging rectangle beam in and get a round beam out you can well bet you are clipping and wasting power.
The input lens diameter and output lens diameter are too small to hold 10X with the more divergent MM diodes, especially when optically corrected, in my experience.
For example a 6X cyl corrected NUBM44 with a G2 primary makes about a 7mm wide ribbon beam that is wider than the input and even if it would accept the full 7mm beam width the output lens is not 10X the input much less 10x 7mm i.e. 70mm and you want that to occupy 80% of the output/objective lens.
Some people have had decent results with stage one divergence MM diodes, Lifetime17 built a NDB7875 with the 10X that worked pretty well but I believe he had to short focus ( less than infinity ) the primary and it was not a corrected beam, however he got good results.
I would not use it for the NUBM44 or NUBM08 and I really don't like it for any of the more divergent MM diodes, I have a NDB7875 with a G2 and Sanwu 3X that works very well, and you can short focus those stage 1 divergence diodes and still get maybe a 5X equivalent from the 10X ( ESTIMATED ) but I don't know how much of the 7A75 or 05/06/07 you can actually get through and how short you would have to focus your primary, in my opinion the lens diameter both input and output are too narrow to get the full 10X out of an infinity focused primary or corrected beam from anything other than DPSS and stage 1 and possibly stage 2 divergence MM diodes without short focusing the primary which means short changing the 10X vs an infinity focused beam and the 3XBE or a BE with wider lenses for the magnification power.
But this is just my experience, someone with a LPM who has a 10X on a 07 or 7A75 could tell you what they get at 100 feet, now you can cheat it to work short range such as I did with this 07 at short distance, but that's not really the purpose of a big BE, it's to reach way out and that's where it seems to fail with the more divergent MM diodes. ( In my experience. )
p.s. It may be possible to use some correction and then telescopic reduction before the 10XBE but as one lens can effect the next I don't know how well that would work, also the more glass in an optical train the more parasitic loss, much can be mitigated with proper AR coatings although any uncoated lenses can eat up around 5% each from what I have read. A wider input/output lens expander to achieve 10X would be my recommendation for use with our more divergent MM diodes, or step down on mag to the 3X and keep the lens diameter more manageable.
