We bought new, a 2001 RX300 AWD,.,,1MZFE(that's the 3.0L V6) and had it for 15 years.
YES!...to answer your question about using a longer filter such as the 3600 size. You can use this size and it'll fit. However, just barely and I don't recall having any problems getting the filter in or out.. I did this several time on our RX without issues. The only reason that I stopped was because of my own concerns.
I felt that the filter was just a bit too close to the front exhaust manifold for my liking.The filter didn't touch the exhaust manifold and it never showed any signs of being burnt or burning through the filter can. So, it was just my own worries!
But, whether using the #3614 or #3600, the filter is a pain to install/remove especially when the manifold is HOT and I always had a small oil mess.
I still belong to Club Lexus Forum and others I've chatted with have used a longer filter and probably still do, IDK. So, take that for what it's worth and good luck with your RX.
CB