Just make sure the chain is long enough. If the chain is too short, shifting into the big/big rings can damage the rear derailleur, hanger, dropout and even the wheel, causing a crash. I've seen it a couple of times on group rides.
Some folks will say they prefer to keep the chain as short as possible and simply won't shift into the big/big. Well, the problem is that under pressure eventually we can all make that mistake. Yeah, in ideal circumstances you can actually hear cross-chaining -- it'll get a little noisier. And there's a slight increase in drivetrain friction. But on a noisy road with wind and traffic drowning out our bike noise, huffing it to close a gap in the group or stomp up a short, steep climb... we can all make the mistake of shifting into the big/big. And if the chain is too short it's gonna be a bad day.
When installing a new chain I always leave it a little long, check the bike on the stand or on a trainer, do several shifts to the extremes of cross-chaining to be sure it's safe. I'll remove one link at a time until it's as short as it can safely be. Or, if I had already done that with the chain I'm replacing, I'll use it as a guide (allowing for elongation from chain wear).
The problem with leaving the chain a little long is increased chain slap, dinging the paint on the right side chain stay. I need to replace the old plastic chainstay guard on my old steel bike for that reason. I noticed the other day the paint is chipped where the old plastic protector has fallen off. I think some folks recommend helicopter tape as a replacement for the chainstay protector.
That's a common issue with some chainring combos. I have mine set up with 52/39 now, and have gone with 38T small ring on some occasions. That means there's a bit of chain slop when I'm in the small chainring, especially with the short cage rear derailleur. My bike with long cage rear derailleur seems to have enough takeup to minimize chain slap.