I think based on what you have posted sir, removing the BS would equate to better fuel economy. However, let's talk of purpose. I'm sure the BS is there not to provide just better mileage but for a lot more reasons.
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The main purpose of most balance shafts are to dampen unwanted vibrations from the motor. The motor is already “balanced”. It is setup for only a certain rpm range and not actual whole rev range. So when removing it you shouldnt feel vibration every where in the rpm range. For example in the sentra (with oem motor mounts) I noticed slight vibration at around 4k-4.5k area only. Other cars might have slightly broader range of vibration or start from lower or higher rpm. Some car companies install balance shafts on the US vehicles but leave them out for the same motor/model that are sold in other Regions . Balance shafts are typically found in in inline motor vehicles , example inline 4..
i ran my 2.3L mazda3 without a balance shaft for nearly 100k. the Balance shaft delete was a popular mod for the naturally aspirated 3 guys.
it allowed the engine to be a bit more free revving (comparable to going from a stock flywheel to a lighter flywheel) wasn't much of a hp gain nor did i see a huge mpg gain.
Different motor brands will react differently. Fortunate for myself with the Sentra 2.5 L motor I cant say I felt HP but I noticed the MPG improvement that made it well worth the effort. I also noticed it revved quicker in neutral. Who knows, the CX-5 motor might react same way as my sentra, better, similar to your 2.3L or even less difference . We wont know unless someone actually removes it.