If a SF drive is throttled or not depends on the settings the vendor selects. That is equally true for the SF-2281.

According to Mushkin:

"DuraClass management functionality is still active. “Unthrottled” in this context refers to write IOPS bursting up to 90,000+ but being governed down to 20,000 after a few seconds which is typical behavior with standard firmware with SF-2281. The firmware we have on the Chronos and Chronos Deluxe drives will not have that governor activated."

Excluding the burst speed throttling there is also a different type of throttling implementation that brings the drive to its knees if you write "excessively" for a sustained period.

The only way of alleviating that is idle time, which is completely retarded, as it has no relevance to the date on the receipt.

SE will not clear this. That data is held in a secure area of the drive. You can SE your drive once or a hundred times. It won't clear it.

I would suggest that if you are able to restore performance via a SE the drive was most likely in a degraded (not throttled) state.