Command update rate for LM629 using 4Mhz crystal?

Hello,

I want to inquire command update rate for LM629, using 4Mhz crystal?

Section 5.6.2 of document "AN-706 LM628/629, SNOA184D–October 1993–Revised May 2013"; states for 8Mhz/6Mhz crystal frequencies:

5.6.2 Command Update Rate
If an LM628/629 is updated too frequently by the host it will not keep up with the commands given. The
LM628/629 aborts the current trajectory calculation when it receives a new STT command, resulting in the
output staying at the value of the previous sample. For this reason it is recommended that trajectory is not
updated at a greater rate than once every 10 ms.

Thank you,

A. Zaheer