@devnull Short answer is "Yes".
Guide mode belay devices released by a 'biner are largely, due to the way the blocking works, an on/off proposition when it comes to the braking applied to the rope - it's very hard/all but impossible to control the lower well especially over long distances. In the "braking off" position, you're relying increasingly on strength for control, which gets worse the heavier the climber. There are various ways to mitigate this, but it required quite a bit of knowledge and practice to do safely.
This is not to say it's impossible to fully lower in guide mode, but not a great option.
@jcmchammy@mountains.social thank you so much for the detailed response, that's very helpful!
Let's say you're in a single pitch context where your follower wasn't able to get past a crux, etc., would you then switch to a redirected belay to lower? 3:1 haul?
DaanSchone
Easiest is to leave the device in guide mode and use it as progress capturing while hauling. You can try to attach yourself with a prusik on the brake strand and weight it with your body, while pulling on the climber's side of the rope. For passing a crux this should be enough.