has anyone tried blending worts?

has anyone tried something like this?

each time you do a batch, make it +1 gallon, so if you usually do 5.5gallon batches make it 6.5gallons. then put the extra gallon in a no-chill container(no yeast). then do that each time you brew so by the 5th brewday, you have 5gallons of mixed wort, add yeast and ferment?

or

during the boil, add another gallon to the mashtun(with the grains you just used), and add the gallon to a container. and do that each brewday untill you have enough as you want. so for example, you would have a gallon runoff of an ipa, a pale ale, a stout, a blonde, and aanother pale ale, for 5gallons of mystery beer to make?

I've seen people blend two batches, but never 5 and never in the way that you mention. There is the risk of infection if the wort is sitting around that long. You might be better off fermenting the extra gallon on its own and blending it after.

What I like to do is brew a little extra and experiment with the last 3/4-1gal - use a different yeast, dry hop with something different, add fruits. I have never blended, but that is something I want to try in the future.

I wouldn't want to have wort sitting around for more than a day or two. Blending beers was extremely common, I do it myself. But one pint at a time.

people have the no-chill containers sitting around for months though with no infections

You could freeze it if you had a leak-proof plastic container that would handle the swelling.