The write count and access speed of the UFM of MAX V devices are described below.

The MAX V DeviceHandbook states that the maximum number of UFM Erase and Reprogramming operations is 1000. (CFM up to 100 times)
For details, please refer to the Device Handbook at the URL link below and search for the keyword "Programming/Erasure Specifications".

For the access speed, search for the keyword "UFM Block Internal Timing Microparameters" from the Device Handbook at the URL link below.

MAX V Handbook URL:
  https://www.altera.com/en_US/pdfs/literature/hb/max-v/max5_handbook.pdf