There are numerous recent papers and work on Spiro and Clothoids.
They may be of help for a Factory or two? Or maybe another Clothoid script?
Here are some links.

https://packagehub.suse.com/packages/libspiro/
https://www.freshports.org/graphics/libspiro
Quote from the above link:
"Spiro is the creation of Raph Levien. It simplifies the drawing of beautiful curves."
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New-ish clothoid papers:

The next link relates to C++ and MatLab (also see second link):
https://github.com/ebertolazzi/Clothoids

The next link relates to C++ and MatLab interface:
http://www.seminariomatematico.polito.it/rendiconti/76-2/47.pdf

The link above mentions the following 2013 paper:
The 2013 paper: (I think that this is the one that the clothoid2pt MoI script is based upon.)
Fast and accurate G1 fitting of clothoid curves:
https://arxiv.org/pdf/1305.6644.pdf

The next link looks like an interesting paper, related to the others:
https://igl.ethz.ch/projects/monocurve/CRC_Paper_Local_Mono_Curve.pdf

https://ebertolazzi.github.io/Clothoids/

https://reader.elsevier.com/reader/sd/pii/S0377042718301924?token=15A5C66BFE8ACE1DF5258C24E51202198AF506A9F86981636170E3E20F4E400CD661F9A5B3FF794442108A16A7D02EE2&originRegion=us-east-1&originCreation=20221130054229

https://www.researchgate.net/profile/Marco-Frego/publication/336354795_Efficient_intersection_between_splines_of_clothoids/links/5e62ce3d92851c7ce04d0d90/Efficient-intersection-between-splines-of-clothoids.pdf

The next link is Pay Per View, or pay for download $59.00. Maybe their other papers cover the ground?:
https://onlinelibrary.wiley.com/doi/10.1002/mma.4700
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Re: Python implementation.
https://pypi.org/project/pyclothoids/

- Brian
(I am barely able to understand a portion of the above papers:-)