@Anuwak @RJDB There is no guaranteed allotment even if you cross 0.5x oversub with no other co-applicant.
In this case your chances of allotment will be increased but no guarantee.
For 100% confirmed allotment, one has to cross 1x of oversub (for practical purposes > 0.6x should get allotment most of the times, as I've seen in many BOAs).
There may be other single applicants at 0.55x, 0.6x ... 0.8, 0.99x, etc along with 0.5x, first these higher category applicants will be allocated one lot post that if there are any shares left to form the lot then only lower category applicants will be allotted.