"due to that UGB" ...
Man, developers always say that, and it's simply never been true. There's so much undeveloped land still within the UGB, and so many opportunities to build densely close into city limits--a lot of which is happening, but a lot more of which could still happen.
Portland does have a big housing problem, it's true, but the solution isn't in opening up the UGB--it's in getting more good jobs, and encouraging more entrepreneurship, so that folks can actually afford to buy the condos going up all over that city.