No matter what you decide, the execution is paramount.
I have sailed for 4 years on an '85 C & C 32, originally built with the standard fin keel. One of the two previous owners reduced the draft to the designed optional centerboard draft and installed a bulb. Not sure, but it may have been installed at the yard I worked at in the '80s. While the bulb dealt with the draft target there were two negative changes -
1) the boat exhibits considerable weatherhelm upwind with winds over about 12-15 knots resulting in difficult steering, regardless of any tuning changes, although reefing the main does help. We have shifted weight, filled tanks, emptied tanks, with little result. When we are heading upwind we try to cram as much crew weight as possible aft. The conclusion is that when the draft was reduced water flow to the rudder changed. When observing the same model with factory installed centerboard the keel profile runs further aft. The rudder is the same on each option. Of course, none of us are engineers or designers and the only advise we are getting is 'buy a new keel'. The Mars website has great and thorough installation instructions, that definitely should be followed. In the long run this installation is questionable and my feeling is (from working in a number of yards for 22 years) that the bulb installation was likely a yard manager stepping back and telling the staff "ok, put it there" (yes that does happen).
2) the owner now has an anomoly and will eventually be looking for a buyer that wants this arrangement or does not have a clue about it's uniqueness. Regardless, the resale value is likely tarnished compared to others that are as originally built.
So, my advise is think twice about what you are considering, get thorough professional advice, weigh the immediate and future costs. Your original question was about protecting your encapsulated ballast. The reality is everybody runs aground sooner or later, often because we are not always where we think we are. Hopefully your boat was built tough enough to withstand the occassional bump or grounding, depending on the bottom material of course, and the big risk is mostly cosmetic.