Sorry that all the advice you might have read starts to become confusing, I think that comes from everyone, including me, trying to finesse the process.  I'm not going to type a whole lot here, as much has already been typed elsewhere, and it sounds like you've read most of that.  But here's a short version of advice (and of course is one man's opinion).

Even if it was really warm and dry at the time you did the spay finish, 8 coats per day sounds like a lot.  And even if very thin and volatile as you say, I'd worry that your underlying coats will take "forever" to get nice and hard - I'm thinking months.  But I'm sure if used carefully everything there will be fine.

As to your upcoming brush-varnish job, going for a quick, multi-coat build up could be even more problematic with respect getting underlying coats to dry/harden properly. Ever notice how you can find a drip or run on an old varnish job that is still soft inside a year later? The same effect, to a lesser degree is taking place if an underlying coat gets sealed in prior to offgassing the VOCs.

My basic suggestion is to follow the directions on the can until you feel confident with trying some slight modifications - usually based on use of thinner, and the weather at the time of application. The company spent a lot of time trying to get their directions right so that customers remain satisfied with their product. That typically means about 1 coat per day, with at least a scuff sanding (brown or white scotchbrite pad, or 400 grit) between coats.  After 3 or 4 coats are on it is usually good to slightly more agressively sand out imperfections, then go ahead with several more coats.  In fact, I feel that going for multiple coats/day can actually increase overall time. Put on one coat/day and each coat is dry every 24 hours.  Put on 3 coats in one day and it might be 5 or more days for the 3 coats to dry.

And don't confuse varnish with epoxy. If properly mixed, epoxy hardens via a chemical reaction, independent of the volume/thickness/presence of air.  Totally different process to harden varnish.

   Thanks for the reply Bubblehead. I I knew 8 coats/day would evoke some gasps but I waited till the prior coat was tack free. Thought that if it didn't work it would just be on the seats but everything looks great and is hard as nails. I did the spraying at the peak of Texas summer because it was to hot for anything else, so it has been several months. 
    I understand what you are saying about comparing vanish with epoxy. The only comparison that I wanted to make was thinking that I wanted a chemical/primary/molecular bond vs a mechanical bond and less time and sanding between coats would be a big plus. I tend to follow directions on the can but also understand that the manufacturer has to do it in one generic conservative paragraph for a general audience. I've read on other sites about doing multiple coats/day with good results but... I have to revert back to the old saying "good judgement comes from experience which comes from bad judgement ". Thanks for the advice! SB