In general I would say no but if you are inexperienced and your yard has 'clutter' that is going to leap out into the path of the mini then possibly yes.
That said I think they will present more surface area for the wind to catch and their weight may trigger payload mode which will if triggered introduce height and distance limits that may be constricting
@Reef hi i think you are talking about the prop holders that go on the drone in the case ,to stop the props being damaged during transport yes they do work just make sure that the props are folded together so they are not being bent ,if i am wrong then i apologise in advance
I've never used prop holders, and always store my MM in the flymore case. I'm still on the original props after 10mths, and haven't had any issues with them. Many of the prop holder designs put some pressure on the blades that could bend them out of shape. Personally I'm not a fan, and find the flymore case does a good job at protecting the blades without any aftermarket add-ons. Others seem to have had success with some types of holder, or even home made straps/bits of velcro etc.
I've used them twice - once for indoor flying, once in the woods to protect against branches. If there is zero wind you can use them, otherwise don't bother and just be careful. Worst I've made contact with so far is a leaf which didn't really affect the drone (no guards), and this is my first drone so not like I'm super experienced flying or anything. I don't even know where the guards are now tbh.
Edit: read some replies, i just put it in the flymore case and fold the props in, no issues at all and I can't see a need for anything else.