Wii model LU64+

So, a friend of mine has asked me to assist him in installing the Homebrew Channel on his Wii. I am kind of a noob at this, but over the summer, I installed it on both mine and another friends. However, this friend has a Wii with model number LU84392690. I remember reading something on a few websites claming that Wiis with model numbers above LU64 are much riskier to hack, and have more of a chance of being bricked. However, every thing I saw about this was from 2009. So does the newest version of the HackMii installer safely and reliably work with LU64+ Wiis, or is it still dangerous? If so, how dangerous is it?

The HackMii Installer works fine on all Wii's.

Thank you for informing me of this.