Have you discussed your plan with a strata lawyer? It isn’t easy to get compensation due to water proofing failures, and the success for that will depend on your proving that the Owners Corporation neglected to carry out proper maintenance of the common property. A strata lawyer can determine if you have a reasonable claim, and how the anticipated change of ownership will affect any claim.
More information can be found here https://www.bannermans.com.au/library/claims-by-owners-for-damages-caused-by-water-ingress-under-s1065/
But be aware that there are a lot of other cases where compensation for loss of rent was not awarded.