I am being force to upgrade my DNN 4.8 site to 5.2.1 by my hosting company (PowerDNN) will I have any know issue with compatibility and for formatting when this upgrade happens.

In order to run XMod on DNN 5.x, you will need to upgrade to XMod 5.5. Previous versions of XMod are not fully compatible with DNN 5+. Only version 5.5 and later is compatbile. FYI, the download for XMod 5.5 contains DNN 4.x-compatible versions as well.