How to lower rsize and wsize of mounted disk?

Hello,
I use Docker for PHP development and since Beta 21 performance got worse (10s of percent) to a point that makes DfW unusable.
I figured out it’s because of rsize option on cifs mount.

My projects consists of hundreds of small files (~1kb) that are loaded on every request.

Option values for versions prior to Beta 23:
rsize=61440,wsize=65536
and since Beta 23:
rsize=1048576,wsize=1048576

Is there any way to change these values?