Performance of 9 rotary encoders + mcp23017

Hello everybody.
I am a beginner in Arduino and I have a fixed project in mind.
I want to create a MIDI table using 9 rotary encoders and something like 40 pushbuttons for photo editing buttons in the Lightroom program.
I have studied and read a lot about using connecting rotary encoders on mcp23017 on arduino leonardo.
The encoders will be rotated 1 at a time and the buttons will also be pressed 1 at a time.
The questions are:
-with 2 mcp23017 on i2c, would the rotary encoder performance be slow?
Has anyone had this experience?