This is a good approach, I might start following it. Nibbling here and there is ideal for this stock which moves sideways for long stretches.
I was also thinking about my exit strategy today. If there's no IPO and stock doesn't move up by at least 20% in a year, I will start reducing by position by 20% every year in January. I don't envision this happening as BIAL value continues to grow, but if it does end up being the case I need a plan.
The biggest risk / worst case I see is a take under by Fairfax. If you look at Atlas or Kennedy Wilson the pattern is there and we would be foolish to ignore it. And it will happen at the worst possible time! If Fairfax India drops to $10-12 or discount continues to get larger, we will be taken out at some point for a 20% premium. Especially as cash in parent FF continues to grow. I would be really upset if BIAL is taken away from us right when it's starting to explode, but I'm mentally prepared for it.
If you're a poor shmuck who decided to buy Kennedy Wilson (partly because of the trust you had in Fairfax) and decided to hold through thick and thin, your 5 and 10 year return is a 50-60% permanent loss (permanent being the keyword). Sure they gave a 40% premium from the absolute lows Same with Atlas but just worse because you were the minority shareholder who helped fund the business during the early stages.