Unfortunately there was no official statement to my comment on topic
http://feedback.jedox.com/forums/220460-jedox-feature-voting-tool?query=cancel
Thats why I opened the same feature reqest again.
The main problem is, that during calculations in web the frontend (in standalone environments) is not responding to any user action.
Please note my comment to the official declination post:
Not aware of long running calculation in Spreadsheet itself other than those related to OLAP and these are controllable via System Manager / Sessions / Jobs."
Sorry, but I think this is still an issue for all standalone-entvironments (especially when running rule-based databases or working with huge dynaranges).
I don't want any user to access or use the System Manager except for admin group.