You are right. Filed level would be FL290. Of course subject to ATC, non-RNP10 aircraft can be cleared above FL290 subject to vertical separation on adjacent tracks! Well that's what I understand from the AIP supplement I read. So quite restrictive..you need to be separated longitudinally from traffic on the track you fly and also vertically separated from traffic on the adjacent track which are about 60nm apart. If you are RNP10 then no problems. Problem for us is ..we are actually RNAV capable but lack redundancy, hence unable RNP10.