Exactly what does the cap table have to do with your expected outcome, presuming you know the percentage of your allocation, the liquidation preferences and valuation, and the company's runway?
The cap table is, to this whole conversation, a MacGuffin.
Also, does it really matter if I know? A later round could have wildly different liquidation preferences that wipe out my gains, right? Though I guess that's true of dilution as well...
Most engineers who join startups think that the 0.03% allocated when they join will be increased later on, and that the initial grant is just a "teaser". I mean, it has to improve, just because it's so ridiculously low, right? (Well, no. In fact, it usually won't.)
Perhaps 5 percent of the engineers who join VC-funded startups would still join if they knew that (a) their equity allotments wouldn't improve, and (b) the founders wouldn't take a personal interest in furnishing them with the connections/credibility to be founders in their next gig. That number becomes closer to 1-2 percent when you're talking about good engineers.
Having the cap table --- which you won't get anyways --- does not actually help you here. A feeling of entitlement isn't what gets you improved compensation. An understanding of your value on the market and a willingness to stand up for yourself is what does that.
Put differently: so what if the cap table suggests you're unlikely to get an improved allocation? If you're worth an improved allocation, you'll get one or the company will lose you.