Agreed, even though I didn't buy any subsale unit in the end. But I have viewed a few before, including the ones which are currently tenanted. Dropped those in the end as I do not want to deal with this hassle at all.

I recall one unit at Lido Residency where 2 sisters are renting there. Imagine the shock on their faces when they saw me and an SA there viewing it. They were under the impression that they're renting it for 2 years but the rental agreement they signed was a 1+1 type, so that means the +1 part entitles the owner to sell/take possession of the unit as explained by the SA to them. Best to let them sort it out between themselves and the unit owner.