I tried diy yeast/sugar co2 once and it leaked once. The smell was awful with a capital AWFUL. Also the aquariums I run co2 on currently are all 75g+ and 3/4 run sumps while the 4th has a giant sponge filter with an airstone in it going 24/7 (it was supposed to just be for skipping cycling but I just let it stay in there because I've overstocked it.) The size of these yeast batches would be crazy... I might as well start a brewery.
Gotta replace it constantly for any kind of consistency, I can manage that for like BBS or some such, but never again will I waste my time on diy co2.
Maybe if I was only running 1 small to mediocre sized tank, but I just don't have the patience to be maintaining diy co2 nonsense instead of the things I actually want to do.