This set includes no less than 24 secret rares, thus unsurprisingly some cards have incredibly low pull rates - 1 in 1000 packs according to the model shown in the rarity table below; I even needed to add an extra color, black to designate pull rates lower than 1 in 800, and change the font size in the cell:
In my model, all 24 secret rares have a pull rate of 1 in 1000 packs, being each printed 3 times on the 10x10 full art Trainers/secret rare sheet and thus taking up 72 slots on the sheet, leaving 28 for the full arts. This leads to 0.86 secret rares per box on average.
Of course, I could have modelled this differently, assuming all 3 full arts printed 10 times on the sheet, 22 secret rares 3 times and the remaining 2 secret rares only 2 times, which would give them pull rates of 1 in 1500 packs. The reason I modelled the set as I did is because the video mentioned in earlier posts which shows how Pokémon cards are made shows part of this very same sheet. The upper part looks as follows (green denoting full arts, pink and red rainbow rares and yellow secret rare items and Energy cards):
The more or less regular pattern leads me to the conclusion that the upper five rows likely contain 14 full arts and 36 secret rares. If the same is assumed for the lower half, there would be 72 secret rares on the sheet, with each one likely printed 3 times, thus avoiding making two of them significantly rarer than the others.
The raw data - including that from Derium’s videos for the Pokémon-GX, full arts and secret rares - is shown at the bottom. The only noteworthy thing about it is that the two non-holo rares which appear as theme deck exclusive holos, Lunala and Solgaleo, appear to be significantly rarer than the others; my estimate is each of the two appears 3 times on the sheet.