Is this distortion acceptable on a 93 dB tweeter?

What made you want this particular tweeter?
I diden´t actually.
It pop´t up a offer to buy a new pair in box for 45% of ordenary price, so i begain to investigate the tweeter.

And find out that it had been used by quite respectable manufacturers, so therefore still a little interested.
The prices of everything in DIY have become too expensive, so it will also be very affordable comparatively.
 
No, it is not acceptable. I use SB26ADC as a sort of baseline - it is widely available, costs ~$55, usable from ~1500 Hz, have good dispersion, and distortion is below -50..-55 dB at 90 dB at 1 m.
SB26ADC distortion at 90 dB

SB26ADC dispersion

(measurement courtesy of @HiFiCompass )

To put it in a further perspective, LP 90.28/N92 has more distortion at 90 dB than SB26 at 105 dB, assuming the chart from dibirama is reliable. Frequency response is weird too, XO design will be more troublesome than basically with any other tweeter.