when you're stretching a tyre on a rim, you are using a skinny tyre that is too skinny for the rim. ie, not very wide. so you could get a much wider tyre on such a rim.
just a commonly used example, a lot of people stretch 215/45R17 on 17x9, ive done this too. now, with a 9" rim you can fit 255/40R17 on there no worries. now going by the rule of thumb that the width is in mm, you now have ~19% more rubber on the ground. thats a fair bit!
given you will have a bit more flex as the sidewall is slightly taller (5mm) and you arent stretching it, but i would rather go for the more grip personally. even for drift, means you have more grip and can go a lot faster, and hold bigger entries.
on standard rims i've run 225/50 and 205/55, and i liked the 205/55s much better. given it probly wasnt a fair test because i ran good yokohamas in the 205/55 and run of the mill 225/50s, but the 225/50 just felt a lot sloppier