What is the Training Value of Lab Testing?

As I approach the end of month 5 of a 12-month plan to begin racing again, I feel like I will soon be fit enough to get serious with my training. To date, my training plan has been pretty casual: 14-20 hrs/wk on the bike, mostly at 75%MHR with a mix of L4, L5 & L6 (AC schema) intervals 2x/wk after the first 2 months. As I prepare for the next, more complex, more challenging phase, I am considering all the resources currently or potentially at my disposal to maximize the results of my efforts. The two resources I have not used to date but which are available to me are: (1) a coach via PM file review and dialogue; and (2) lab testing. There are a few labs within relatively easy access (e.g., San Diego) that can do VO2MAX and LT testing, etc. Actually, there may be a lab at UNLV, which would be even better. There is a cost (~$200/test), so it's not free (to me). As with any economic decision, it comes down to cost/benefit. I would envision getting tested maybe three times (Sept, Dec, Mar). I see this as a decision indepedent of hiring a coach, although obviously a coach could probably help me interpret and exploit the test data better than I could do by myself. My questions are: Would lab test data enable me (with or w/o a coach) to design more effective training plans to, say, target different adaptations? Would lab test data on my own individual lactate recovery rates from different intensities >LT enable me to be more precise in estimating my recovery requirements from pushes >LT in TTs? Would lab test data provide any other benefits I haven't thought of?