This particular discussion started in what would have been late winter here in Iowa. Now mid fall a year and a half later, I still use Ultimate Liquid Wax on most, if not all, of the cars I detail other than my own. I tend to experiment more on our own cars. The majority of the cars I detail are daily drivers and Ultimate Wax has Meguiar's stamp of approval as being their wax with the best longevity in most cases. Keep in mind a busy month for me is a car or two a week. So when I say cars, it's not that many and when the temperatures were floating around 100, I took a break and enjoyed the air conditioning of home rather than detail cars.
This week I worked on a new, black, Honda CRV and I used Ultimate Liquid Wax. I'm a slow worker and the folks that bring their cars to me know it is a multiple day process. Day one is wash, dry, clay, tape off and establish test areas. Day two is corrective work and at the end of the day, application of the first coat of Ultimate Liquid Wax. I've used some variation of the 3-5 minute wait time method to the different "apply - go to lunch" and return later to buff off the wax method. I understand temperature and humidity influence when the product is wiped off. I know what causes streaking, at least for me, and I can "on purpose", through experimentation, will have the wax streak when 1) apply it too thick and 2) over work it (the majority of my application is via a PC with a 4" pad). Applying too much will nearly always result in streaking and running the buffer over an area repeatedly will result in streaking. In the areas I apply by hand I often will mistakenly apply the product too thick and can have streaking.
As I stated, I apply the first coat of Ultimate Liquid Wax at the end of the second day. The cure time is over night and I usually clean the windows in the morning of the third day first and then apply the second coat of wax after cleaning the glass. Remember the second coat of wax isn't necessarily a "second coat of wax", it is more to insure coverage in areas you may have missed.
I haven't yet need to try the mist water and buff technique. It has not been needed. If I see a streak, I wipe it out. Technically I don't know what is happening, but it feels like I'm just spreading the streak out and it disappears. I work in a poorly lit, mechanics area of an old car dealership. When the owner comes to pick up their car, we often take the car outdoors and review it in the sunlight before the owner drives away. If I see a streak, it simply wipes away.
In my limited experience, "keep it thin to win" is my mantra. I'm sorry you've had difficulties, some folks feel using the paste version of Ultimate Wax is best to avoid streaking. I wouldn't know, as I have always used and will continue to use the liquid version of Ultimate Wax. At least until Meguiar's makes another wax with a professed longer...longevity. Oh and the new wax would need to provide the mirror-like, razor sharp reflections of ULW.