There are likely some small changes in the schema.
I would use the following flow.
backup everything
create your current db clone
install jsreport 2.8.0 and run it configured to the db clone
test the app, it can fail on some schema errors, typically with error "missing column jsreport_TemplateType"
run alter table jsreport_TemplateType <column> <datatype>, you can get the type from
http://localhost:5488/odata/$metadata
when everything works, you can use the same alters on your current db and update jsreport