I don't know about the 105, but the Ultegra HG800 11-34 11 speed cassette has many of the larger cogs on spiders with solid splines. So it will help prevent your freehub from getting notched up, especially if you have an aluminum one. I've got two of them, one of which is on a DT Swiss alloy freehub. If you take the cassette off you can see the hub splines are clean up until the smallest 3 or 4 cogs, where you can see little notches starting to form (this is after like 3-4K miles, so plenty of life left on this freehub). Like I said, I don't know if the 105 has the same thing.

Fun fact: The Ultegra cassette works great on 10-speed freehubs. That's because the 34t cog is large enough that it can use the MTB trick of letting the big cog sit inboard a little ways without running into the spokes. For all I know it might just be a rebadged XT cassette. You need a spacer (I think it's included) to run it on a true 11 speed freehub.

Edit: Here's a picture of the cog carriers on the cassette (it's the second picture, which doesn't display by default, so you have to click on the thumbnail to bring it up). This vendor also sells the 105 version, but there's no photo from the backside so it's unclear how it's assembled.

https://www.competitivecyclist.com/s...hg800-cassette