My only "expertise" beyond having recently stayed at a Holiday Inn Express is having seen various stock options from 3 different large Fortune 1000 companies. In the first, some of the options had matured, some had not... but a RIF occured and even though we were blind sided by the RIF, and we had no documentation accounting for the mechanics of "What if..." part of the exit package was "... we have aged all your options strike points" meaning the only caveat was we had to execute within 90 days of termination. So while faced with severance, we still had to fund a five figure expense to aquire a six figure cash out. Fortunately had access to the means to do so, and another "unknown unknown" application for an well funded emergency fund.
After relanding at another F1000, another 5 years go by with a number of both matured and "seven year cliffed" RSU's are aquired when the RIF grim reeper taps us on the shoulder to tell us "the music stopped, you don't have a chair". This time, a 60 page severence agreement, including "you can not work for X,Y or Z competitors" was carrotted on a very fair severence agreement. However, the most lucrative "7 year" RSU's that today would have been worth mid to upper 6 figures were not going to be grandfathered.
We went to our attorney to review the severence and his $1800 worth of advice was ... "Wow, I have reviewed a bunch of these exit packages and and this one is unbelievably well written... If you want to sue them... you are going to need a bigger boat". HOWEVER, he suggested asking them if they would consider reducing your monthly severence amount and extending the period until your official end date, allowing you to extend your benefits window and achieve at least your next batch of options. Since we were very careful to "exit" professionally, they allowed us to do that, in effect being on the employee count for an additional 4 months until the next level of options aged. We signed on that, even though it cut our monthly severence to about 65%.
What did suprise us, and was totally NOT in our calculations was that by being an "employee" on a certain date also triggered a entire annual profit share even though separation was in Q1.
So, my "Dad thinks..." advice for you is don't sweat the "onerous legal wording" of your current options as there is not much you can do about them. If you get IPOed, chances are the rules in play will be established by the buyers, and their HR department rules, and the regulations they play by...and unless you are talking about a 6 figure bump, up front analysis is over analysis.
Hope this helps.