Does increasing cache size of memory translate to higher I/O speeds?

Hello Android Enthusiasts!

I recently came across this app on the Play Store that claims to increase I/O speeds. On installing it, it showed me that the default cache size for my device is 128KB and the optimal size is 512KB.

My question is, will increasing the cache size to 512KB actually increase I/O speeds? Also, can changing the system defaults cause any adverse effects?

Any help is appreciated.