Ultralight is definitely not abandoned, 1.3-beta will be released end of this week (nightly builds have been available for the past year) and ARM64 support will be available in the 1.4-dev branch later this year.
Feel free to contact me at adam {at} ultralig.ht if you need support or want a refund.
Feel free to contact me at adam {at} ultralig.ht if you need support or want a refund.