Personally, I simply set the parking brake then place the PRNDL in park, get out, then place the small chocks. Haven't had a problem or felt at all unsafe. However, one could place the TV in park and hold the foot brake, which would activate the TV brakes and the TT brakes. As already mentioned, nothing is going anywhere. I also take this opportunity to set my regular chocks on the other side.
Using planks is an effective method of leveling the TT, no doubt, and there are those that can decipher the markings on the bubble that indicate how many planks are required for level (I can, but I wouldn't say it's my favorite thing to do!). I personally have moved away from wood primarily because plastic dries faster, is easier to keep clean, and doesn't give me splinters. These particular levelers have the added benefit of being very effective wheel chocks as well as levelers. I've seen plastic lego type units that try to incorporate some kind of chock in their design, but they don't work nearly as well as these, IMHO.
So many products aimed at us campers are on the market and more are added daily to separate us from our money. Many of those items are a complete waste of money and don't perform as claimed or are flimsy and don't last. While not every new product is for everybody, or even necessarily "better" (it may just be a different way to do the same things), it's always good to know that some new toy you are thinking of buying works as described and won't just end up in a corner of the garage.
2022 Keystone Cougar 24RDS
2023 Ram 6.7L Laramie Mega Cab