I would strongly advise sticking with the factory mount that the M25XPB came with. I my experience & opinion they are a far superior mount to the BI product.
I have to replace more BI mounts than any other single mount... They also transmit a lot more vibration to the boat and are very difficult to dial in to a "comfortable" vibration tolerance level even with an alignment that is dialed into .001".... The factory mounts last longer, are better designed and isolate engine vibrations better. If there is one thing I have learned over the years it is that the current mounts Westebeke/Universal ship with are EXCELLENT quality that do a better job than most aftermarket mounts at effectively isolating engine vibrations to the hull.
Sometimes when a boat already has them, this used to be Universal's factory supplied mount, I will replace them with like if the hole pattern is going to be an issue, but I never "like" doing it..
When I replaced the mounts on my own motor I ponied up for the Westerbeke mounts without question.
Also the hole pattern on BI mounts often does not line up with the factory Westerbeke mount...
A very common failure mode on BI mounts which makes alignment impossible..
And another one:
The factory Westerbeke mount was retired at 2172 hours of use even though they were still technically working. Other than a little sag there were no signs of failure in the rubber or the mount. You can't "spin" the stud on the Westerbeke mount because it is welded to the cover.
The two BI mounts were the second set this boat had installed in less than 800 hours use. One was snapped clean off and the other was spinning in the rubber. All of the mounts on this motor were spinning in the rubber except for the snapped one because I never tried it...