In the August 16, 2023 patch day, they have implemented the ability to use the old UI engine instead of the new UI engine, most likely due to the odd behavior it can give. Until the new UI is 100%, I am recommending to not use it to ensure you do not have any issues on the live server.
To do this, without loading Everquest, simply open up your eqclient.ini and look for the [Defaults] section. Add UseNewUIEngine=0 then save and close, that is all. Or you can do it the long way and load Everquest, look in your Options window, and under the Display tab, bottom right, UN-Check the Use New UI Engine box. You now have to Exit Everquest to desktop and reload.
If you want to play around with the New UI Engine, visit the Test server for all the updates. I am pretty sure it is a long way before it would be something stable enough to move forward with. Also, the way it is now, I cannot see it being very user friendly to create anything with very easily either. As long as they allow to use the Old UI Engine, we are good. If they discontinue that ability, then we have a problem and may be in for a long haul to do any conversions.