Some people use SRT rope climbing to get up into the tree using a mechanical belay device like the Safeguard or the GriGri+ for progress capture and then they stay on that rope and device during their hunt, using their climbing rope as their tether during the hunt. When their hunt is over, they use their belay device for controlled descent back down to the ground.
Related and more informative questions are: Q1: "What are the pros and cons of using a mechanical belay device with your climbing rope as your tree tether?" and Q2: "What is the best practice for tether setup while in hunting position in the tree?"
My answers to both questions:
The pros: (1) There's no transition to a separate, dedicated tether, thus eliminating that step and the risk of incorrectly performing the transition to tether once at hunting height. (2) It also eliminates the transition off of the tether and to a rappel setup when you're ready to descend.
The con: (1) All belay devices, including the Madrock Safeguard, are intended to be used with the tag end of the climbing rope held in a controlled manner by one hand to prevent slack & associated slippage on the rope when it's unweighted. Thus, if you ever stand on your platform or ROS or maneuver around the tree for a shot in a way that unweights your rope, it will be able to slide through the belay device if you haven't introduced a countermeasure to prevent rope from feeding through the device.
The best practice while in hunting position: Have a countermeasure incorporated into your setup at height if you stay on your climbing rope to have it do double-duty as your tether during your hunt. The best countermeasure is a friction hitch placed above the mechanical belay device and connected to the carabiner that is clipped to your mechanical belay device.
WARNING: It is not recommended to place a friction hitch on the tag end of the rope (meaning: below the mechanical belay device) because it is possible for the hitch to feed up against or into the mechanical belay device if the rope slips through the belay device, and the Madrock Safeguard manual specifically warns against implementing a friction hitch on the tag end of the rope, stating that it is possible to BREAK the Safeguard if a backup friction hitch is placed below the Safeguard.
You can view a brief demonstration of how these devices permit rope slip when unweighted, and how to incorporate an optimal countermeasure with a friction hitch placed above the belay device, which I believe is the best practice for tether setup while you are in hunting position if you SRT rope climb into the tree with a mechanical belay device for progress capture during your climb. This video is from a reputable source for saddle hunting supplies, Eastern Woods Outdoors:
Here's one guy's viewpoint on the performance of the Petzl GriGri+ vs. the Madrock Safeguard: