If you want to set up a dual boot configuration with Windows Server 2019 Essentials as your primary OS and Windows 10 Pro as the secondary OS, you have a few options for boot managers.
1. Windows Boot Manager (BCD): The standard Windows boot manager allows you to select between different operating systems installed on your system. This should work fine for a dual boot setup with two OSes. However, it may not support more than two OSes, so if you plan to add more operating systems in the future, you might need a different boot manager.
2. EasyBCD: EasyBCD is a popular third-party boot manager that lets you manage multiple operating systems on your computer. It supports both MBR and GPT-based drives, so it should work well with your...