Need to be clear with the messaging. It's important because conversations here influence decisions that newcomers make. That said, Mad Rock has specified that the Safeguard can be used with ropes down to 8.1mm "for rescue / rigging". They make a distinction between this type of use and "climbing". Now, the difference between these types varies widely from source to source...
Here's a good read taken from Pinnacle Arborists for folks to consider.
"Two of the most important pieces of tree gear you will ever own are your climbing rope and your rigging rope. And it is absolutely essential that you understand the difference between the two. Failing to use them for the right purposes is extremely dangerous and could result in accidents like:
- Deadly or debilitating falls
- Being struck by falling limbs
The Big Difference
The big difference between these two types of tree gear are their primary uses. Climbing rope is the rope that secures you to your saddle and to the tree as you climb up and down. It is made for this purpose and should not be used for anything else.
On the other hand, rigging rope is what you would use to lower and move heavy objects such as cut tree limbs. Again, this rope should not be used for other applications. The wear and tear on a rigging rope should not be used to support you as you climb."
Most sources make a distinction between rigging and climbing by saying that rigging ropes are used or abused in some way (this implies use in abrasive environments). The general idea is that you should never climb on a rope that's already been used for rigging.
Text from Mad Rock's site for reference:
"For rescue / rigging use: 8.1mm to 11mm rope diameter
For climbing use: 8.9mm to 11mm rope diameter"