Don't get it ... asked a question, then answered your own question ... with exception of usage.
Hmmmm ... I can tell you for a fact, that on a standalone ... not shared ... there is a limitation as to the number of installations - space on drive just for code is one ... and with 3.1 if full featured it would mean installation of Apache Solr Search which means an install of JRE (java runtime environment). Many shared hosting providers do NOT install Java anything on shared host. Check that with 1and1 FAQ's/helpdesk/forums. You don't have unlimited drive space on a shared system, do you?
Hard to predict actual usage ... we, here in the forums (I'll speak for myself here), certainly can't do a Vulcan Mind Meld! Only you, the sysop, would know.
Sooooo .... ?????
'spirit of sharing', Ken