Any good data on prop guard degradation on battery life? and leaf blowing.

[gemniii]

Newbie here - Just got and started flying my MM. I'm in fairly dense woods and my prime excuse for getting it was to check my roofs for fallen branches. I've about 6,000 square feet of sheds with overhanging trees that provide significant cooling but also necessitate some cleaning, with the MM I've already monitored the roofs.
But because I fly in the trees (almost) I'm leaving the prop guards on.
I'll gladly trade flight time for prop/AC protection.
But I'm wondering how much it decreases my flight time.
10%, 20%, worse?
And any good hints on leaf blowing? The MM seems like a good leaf blower at low altitude

 

[gemniii]

Found it:

With the propeller guard attached, Mavic Mini offers a maximum flight time of 18 minutes

And I think they just saved me from a crash, I was just starting to land, battery was going low and drone decided to RTH through a "low" (12'AGL) power line running to a security light.