About the hyperexponential horn shape

Thank you for your interest in my task and your willingness to help. I need this for practical implementation. I would like to make a better tweeter horn. Several versions of horns have already been made, but they do not meet my requirements. I really hope that this version will be better than the previous ones.
 
Acoustic system - two-way.
The parameters are quite typical: a tweeter with a diameter of 25 mm, a frequency band of 1200 - 23000 Hz. With the use of tractrissa, good results have been obtained, but the unevenness of the frequency response is more than 3 dB.
The speaker sensitivity is well matched.
May I ask you for a recommendation of an available horn simulator (other than HornResp)?
Thanks in advance.
 
AkAbak is the best AFAIK. I know there's others, but nobody talks about them anymore [at least around here] to the point where I don't remember the names. 🙁

FWIW, true waveguides [WG] is best for HIFI, though at 1200 Hz it ideally needs a [big] 300 Hz Fc.