Rapid tools released UV reactor. A very promising UV unwrap system inside 3ds Max. Unlinke the modifier based UV unwrap modifier included in max, this new tool is modifier independent, so it can be open at all times, totally independent and detached from the modifier panel, more in line in how other software manages UVs.
Is not the only difference, it also uses instruction sets on your CPU to be 8 times faster than any other tool (According to Rapidtools developer). In some tests, 1.5Milions polys with thousands of islands has been packed in less than 7 seconds.
Because is OpenGL accelerated, you can work in UV reactor in real time even with milions of polygons.
And has a huge amount of other advantages, being able to use any selection tool that you are already used to in 3dsmax, new unwrapping and multistiching tools and more. Check the website for mor information.
It supports max 2020 to 2025 and the tool cost 100 euros for an indie license.