I guess I should see what the X5r does, but on my P3P and P3A I would get AWB (automatic white balance) color shifts during recording. For example, if pointed down and I did a tilt up I could see a color shift as it processed the data from green ground to blue sky. This made for inconsistent incoming video and stills. My early video attempts were, well, bad. They took a lot of time to post. Most of it chasing proper color balancing across a clip that changes.
At high noon clear day the normal color temp is about 5600k or so. Late afternoon or early morning its down to near 4800k. Dusk and dawn are closer to 3000k. Cloudy days tend to shift things toward blue by around 1000k because water absorbs the red end of the spectrum. So I looked at the average temps during the times I typically shoot and arrived at 5000k as an easy to remember middle ground. Its a bit down from high noon but not so far off that the stock video is off. And its a bit above the late afternoons, but again, not so far as to look bad out of camera. But it solves the drifting AWB issue. My decision was to change from AWB to custom WB and set it at 5000k.
By shooting every scene and every shot with the same base WB setting, I have a known starting point for post processing. I don't have to guess each time, I know what it was shot at and what I need to do to tweak it to proper WB in post. I made quick start color correction settings in Premiere and in Lightroom for sunny days, cloudy days, summer and winter. I can quickly drop those presets on incoming video and stills to get them color corrected almost immediately. And the ones that aren't close enough, then I can resort to the passport for sampling. But most of the time I simply look at when the video was shot and drop the proper preset on and I am done. Its literally that quick.
I took my time making those presets and got them right to start with and it took hours. But its hours I only have to spend once, not every time I want to run video. I have them set up for 2hr increments from 10am to 4pm which is 99% of my shooting. I have a set for cloudy, a set for sunny for both Winter and Summer (yes the color temp changes seasonally). I simply look at the timestamp and a preview of the clip. It was shot in July on a sunny day at 2pm, so I go to summer, sunny, and drop 1400 on the clip. Done.
That only works if the incoming source was all shot at the same WB. If its shot on AWB then those presets won't work because the incoming source is not the same each time and that means each clip would have to be manually processed. The passport helps and allows a quicker processing. But, if you shoot AWB, the difference between each clip or each image can be substantial depending on what the camera thought was right at that time. And that changes. Constantly.
I shoot manual everything almost always. Rare times I will throw the camera exposure into auto, but that is rare. I typically take a look around at the scene and manually set aperture (I1 not P3), shutter speed and ISO to get an average -0.5ev. That way I won't blow out any whites. And again, I don't have a drifting exposure through a clip. I have a known starting point.
The passport does not fix anything. Its a reference. Like any tool you need to understand how to use it and that its not magic. Buying a CNC machine doesn't mean you can immediately produce a production part from it. Buying a set of calipers doesn't mean you know what to change on the CNC. Buying a passport doesn't immediately fix your video. You need to understand how the tool works with all your other tools. You need to understand how the camera works to use the passport.
I guess what I am trying to tell you is that you may need to change HOW you shoot to make best use of the passport. If you have things on auto in the camera, then what it sees and processed at the time you shot the passport may not be what it sees and processed when its up in the sky over your subject. And that renders the passport completely useless because that scene with the passport is not the same settings as the scene you want to correct.
I am not a pro photog, I am just a hobbyist. But I have been shooting since the 80's using old school manual Minolta SLRs, developing my own film and prints. Despite having a fairly modern Nikon D7K (seriously looking at a D500 or maybe a D850) that has crazy auto settings and one of the best image processors on the market, I turn all that off 99% of the time. I set the WB using a gray card (passport) or ExpoDisk, I shoot a passport during the session. And I set the ISO, aperture and shutter speed for virtually every shot. Bout the only chimping I do is at a histogram once in a while to verify I am still on target or to verify focus. The only exception is shooting sports, you don't have time to set anything. For that I go fixed aperture and fixed SS and let the ISO float for exposure. That way I control DoF and action stopping and let the camera figure out the exposure shot by shot using ISO. Other than that, I guess I am just a manual type of guy. So, take the advice above from this jaded view.