Multi-Axis Guiding Curves performance was improved, but if you have specific cases that used to work slow and you can share those (PRs) that would be great.
when the generation flow is perfect - enhancing the performance by multi-threading is a good idea (and we are working in this direction). yet, a significan performance enhancement was done recently by changing some parasolid calls that on some body types took lomg minutes and now it is seconds. this is why I think that more cases we get - more chances we adjust the processor for various input types.
as was mentioned above - 1847 was released already so you can first try your cases on it and if still slow - Please PR the cases.