I don't think I cast any where near 50y with any presentation I normally throw. I did a test on one of my reels, a Daiwa sv103 with a 34mm spool.
I have the reel spooled with 40lb PP braid;
Again we run into the issue of manufactures just listing "14lb Mono" without giving diameter. Ande IFGA Mono does not come in 14lb, only 16lb and 12lb, but the 12lb is .325 mm, so we can assume that 40lb PP is a little thinner then the ideal 14lb mono.
With the spool filled up to bottom of the lip I am getting ~26" ITP, give or take 1/2" on each side as I used a fat marker to mark the line. I then pulled off line to the half-way mark Daiwa puts on their spools. I tend to fill my spools to this mark with backer and the rest with mainline. When I measured again I was getting around ~22" ITP. So not a huge difference.
In interestingly, when I mentioned noticing a slow down in retrieve speed was over the summer, when I had the same reel spooled up with 65lb Sufix 832.
Now in that case, we are in between Ande IFGA 16lb at .375mm and Ande IFGA 20lb at .425mm. I believe I spooled the Suffix to fill the entire spool and while I never spooled it on a cast, I believe that I was casting off more then half of the spool, but was honestly not paying close attention. I do have a 1016 spool filled with .40mm mono that I will run the same test on in a bit.