Yes, you can do it.
Local Data Cleanup affects only local copies of Teamwork Projects that you were part of. So if you do not have Teamwork Projects you are involved in anymore, and you have all their data saved as Solo Project Files, then you do not need any of their Local Data anymore.
Loving Archicad since 1995 - Find Archicad Tips at x.com/laszlonagy
AMD Ryzen9 5900X CPU, 64 GB RAM 3600 MHz, Nvidia GTX 1060 6GB, 500 GB NVMe SSD
2x28" (2560x1440), Windows 10 PRO ENG, Ac20-Ac28