For security reasons we want to run the handle server and the application container on separate machines. This would even be helpful for institutions running multiple DSpace instances as they would need one handle server only for all instances.
We want the HandlePlugin to connect to a DSpace instance over http(s) instead of using the HandleManager directly. The handle server could run on a separate machine and would neither need access to the HandleManager nor need a database. XMLUI and JSPUI could serve the required information as JSON.
DS-1171 has a similar idea with a different approach. They want the HandleManager to store the handles in an external handle server. This is interesting if you want to use one handle server for DSpace and other software, but it would need some bigger changes to the HandleManager and it would duplicate the information about used handles over two different databases (the database DSpace uses and the database the external handle server uses).