I could be missing something, but I'm not sure that tax loss harvesting with a robo investor is worth all the karate. You can deduct $3,000 of losses year, so the benefit is your top marginal rate times $3,000. Let's say you are in the 22% tax bracket (up to about $165K for MFJ). So your savings would be $660. That's not nothing, certainly. Now, let's say your portfolio is $500,000. Betterment's fee of 0.25% would cost you $1250 in fees. Not a great deal. It works best for people in high tax brackets but small portfolios. The breakeven point in the above example is about $260,000. Above that amount it costs more than the savings.
But it isn't even that good. By harvesting losses now, you are increasing gains in the future. In general, that's probably a good thing, but it does lower the break even point. Since the OP is just starting out, he's probably okay with the robo-investor until he starts to get close to break even. But if he decides to go that route, he put all of his investments with the robovestor so he doesn't accidently violate wash rules.