VFX guru David Torno has finally completed his After Effects scripting pet project, conSOLIDator. conSOLIDator does pretty much what it says. It consolidates the Solids and Nulls in your project files into as few as possible. Now you will have less Solids to look at in your Project Panel.
conSOLIDator – Free & Open Source
David started this little project back 2015 at the request of Harry Frank. However, life got in the way and it was put on the back burner for a while. Then, Victoria Nece, Adobe Product Manager for Motion Graphics and Visual Effects, contacted him about a user request to consolidate nulls and solids. So, he resurrected the scipt, completed it, and is now offering it to the After Effects community.
The script is free and even open source so you can see all the code.
David has more info about this handy script as well as download links and a tutorial on how it works, at ProVideo Coalition.