Scanning the entire spectrum the radio is capable of receiving is an incredibly inefficient task, and something the radio was never really designed to do.
It virtually assures you will miss just about everything you might want to hear.
I don't think you really understand the concept of using a scanner from your post.
Even scanning the full database will only scan the appropriate systems and frequencies in use in your specific area. It does not scan the "full database"
I suppose you could set up a search limit between lowest and highest frequencies the radio can receive, but it will take all day to scan it once, and you will spend the whole day skipping over birdie frequencies and other interference.
What exactly are you trying to receive?
I cannot think of any reason someone would even want to try "scanning everything"
536/436/ws1095/996p2/996xt/325p2/396xt/psr800/396t/HP-1/HP-2 & others
To answer your question and to better explain my reasons, I moved to the 436 after first experiencing the world of scanning with an analogue Bearcat. It didn't have downloadable databases and such, so I found interesting frequencies just by accident and programmed my radio bit by bit as I found things. That was super fin to me. Now, obviously the 436 is a vastly superior machine and capable of digital and analogue reception, but it seems to rely on the downloading of databases and therefore unless someone else has discovered a frequency and added it to the database I'm not going to find it. Using this scanner is not nearly as fun - it feels clinical and pre-determined. I see people in my area on forums like this discuss various frequencies of interest that do not seem to be in my database and I wonder how they found them if not by scanning outside of what was given to them in the database.
Another reason is that I have various tech gadgets around my home that transmit radio frequencies, such as old walkie talkies, a baby monitor, video transmitters, wireless audio equipment, cctv cameras etc. And I want to see if I can find a signal from some of them with my 436. For one example, I own a cheap Chinese baby video and audio monitor (which is actually really good) that I use to keep an eye on my home when I'm in the studio next door, and it did not come with any info regarding frequency of transmission or security. I wanted to see if I could find any kind of signal from it on the scanner in case my privacy is at risk and others could potentially tune into it. This frequency is not going to be included in Uniden's database. And many such products and signals will not be included.
I don't know much about scanners and have probably only put about 50 hours of time into scanning since I got my Bearcat and then quickly upgraded to the 436 about a year ago. I will never be as into this as most of you are - I have other hobbies and don't have the interest in learning the in-depth codes and programming terms that you all talk about. But I like to tune into interesting signals and I always have had an interest in that since my childhood CB days.
I don't hear much that's of interest in my area on this scanner and so I have rarely used it. But today I thought, maybe it would be a lot more interesting if I could find things other than the boring old police, fire and ems that the database offers me. The interesting police are encrypted here so all I get is basically traffic cops talking about traffic incidents. That gets old quickly. Often I can only hear one side of the conversation and so it makes little sense anyway. There must be more interesting signals out there.