I'm almost positive Cantor, as well as most other sportsbooks, will not let you parlay early GOTY-type lines for this very reason. That said, sure if you know you win at over 53% long term, parlay up to 3 teams until the cows come come, but the reason most winning sports bettors don't do it is:
#1 It's a hassle and a time suck that is likely preventing you from finding more games and missing out on better lines.
#2 They don't know all their bets at the same time, therefore you're not going to have a balanced portfolio, (which isn't vital, but it's helpful if your picks aren't weighted).
#3 Even if they DID know all their bets at the same time, let's say I find 4 bets I really like. I bet them straight, then bet the 6 permutations of 2 team parlays, and 4 permutations of 3 teamers. Simple enough, right? Now try that when you like 8 games. 8 games is 28 two teamers, and a bunch more 3 teamers. Unless (and maybe even if) you find a sportsbook that can round-robin these bets automatically, chances are the lines are going to move some before you get a chance to get them all in and now your betting portfolio is unbalanced. Not to mention the fact that if betting online your job has now turned from being a sports bettor to data entry clerk, and I can't think of many better ways to arouse suspicion than to bet massive amounts of round-robin parlays off the board.
#4 I have bet a ton NFL teasers at about a 70% clip per side for my career, almost always betting all available 2 teamers, and often most 3 teamers, and the variance was insane. You're not going to hit 70% of your sides.
#5 Virtually no one properly bets within their bankroll, but at least most guys have an idea of what their swings are gong to look like day-to-day and week-to-week. But if you start parlaying EVERYTHING? Forget about it. Who the hell wants to be constantly be refiguring Kelly sizing?
#6 Pros prefer their parlays to be correlated in at least some way.
My recommendation is if you are only betting a few games a day and/or for smallish amounts, then fine, parlay away if you're confident you're over 53% long-term. But if you're betting 15-40 games a day for solid amounts like me, then you're better off being choosy.