Agreed he'll be turning some high RPMs. As I said, it's (after doing some math) about 83% of the minimum recommended load for that engine. A better way (in my experience) to calculate what fits for pitch/diameter is to take dia*dia*dia*dia*pitch (i.e. dia to the 4th power and multiply by pitch). This gives you a rough "loading" number. This number is only useful as a comparison, it's not a measure of thrust or anything like that. If you do this math for all the recommended props you can establish a "load range" for the airplane and have something to compare to. Then do the same for any prop you are considering and compare to the range. At least you'll have an idea what to expect. Higher load, less RPMs with the expected effect on torque, speed, etc. within the motors capabilities.

I built a spreadsheet where I did the math for everything from 5 to 25 inch props with pitches from 4 to 10 and sorted by load factor. Occaisonally I add a size if I see something odd, like the 12.5 x 14 or whatever it was. Everytime I get a motor I enter in a new column with the range of props that the manufacturer recommends. There will be lots of props that fit in between and occaisonally that can lead to some interesting possibilities. It's fun to then go get two or three options that look like they might fit what you want to accomplish (higher pitch/lower dia for speed... opposite for pull/thrust) and try them out. I've used this method for years and it's a fair predictor if you are comparing similar make to similar make. If nothing else it keeps you out of trouble. If you stay within the load range you will almost never have an issue based on overload or over-rev on an engine. You will also learn quickly which prop types/brands have more overall loading compared to others. Depends on the airfoil design and material properties (less/more flex).

OK, yes, I'm a bit of a geek and love to do these sorts of calculations and then go buy some props and prove it out. I've done it many times and rarely bought a prop that didn't work as expected per the calculations. Here's a sample for the DLE-20:

14 10 384160
16 6 393216
15 8 405000
14 11 422576
16 7 458752
14 12 460992
17 6 501126
15 10 506250
16 8 524288

Would you have guessed a 16x7 and a 14x12 would load the motor almost equally?? That the load seems to very Ok, enough fun with math. Play around with props and enjoy.