The issue is that the distribution of an event like getting an exotic ultra container is very random because the probability is very low
So if the probability is 1%, you would expect to get 10 exotics if you opened 1000 ultra containers
However, the 10 exotics could be in the last 500 you open or something, so opening 200 without getting an exotic isn't that unusual
I haven't got an exotic from ultras for a long time, but I have also got exotics from opening just one ultra container
Some players are going to be more lucky than others

(15000+75000+150000+333000+500000+850000)/2 = 961,500 crystals
Upgrading it from Mk7 to Mk7+ on a 50/50 sale for MUs and SUs would cost 3,080,000 crystals if you don't buy the last speed-up (and wait for 20.5 days to get it to 50%)

You need to go to  TankViewer - 02.12.2020  >  data  >  colormaps  >  custom and replace any of the three .jpg files there with another with the same name (but no larger than 512x512 pixels)
In the viewer, they will be paints 494, 495, and 496
You can replace any of the paints (not just the ones in the custom folder) with your own, but you must give the .jpg the same filename as the one you replace
So for this I just opened "Red.jpg" (in colormaps), which is just a red pixel. I changed the pixel to magenta and saved it as "Red.jpg" and here it is in the viewer
(if you want to use different names, you also have to change the name in the config.xml file which is in the same folder as TankViewer.exe)

"added permanent immunity to all status effects for Juggernaut"

looks like you have accidentally decreased the battle screen size
default keys for it are "=" or numpad "+" to increase its size, and "-" or numpad "-" to decrease its size
one press of the increase key should fix that

Before the Mk update, you could buy the Avalanche Kit (M2 Freeze and M2 Hornet) in the shop at WO2 and in the garage at WO4
If you fully micro-upgraded them to M2.10 before the update, then they got converted to Mk7
It's crazy, but that's what happened