You are stressing analytics way to much on Itch. I don't think that browser plays are counted once per user, but probably not everytime someone plays it. My guess is that it only counts after a certain playtime to prevent spamming reload to fake stats. Also, I don't know where you are seeing these ratios.
Viewing post in info about analytics
Ok, well actually aside the CTR, all the other "<this> through <that>" are not anywhere, i just calculate them, in the same way you can calculate the CTR.
When i say 25% of view turns into browser plays is because in the same time range analytics told me that
y (browser plays) / x (views) = 25% (views are 4 times the browser plays)
same reasoning for any other metric i named, aside the ones actually displayed from itch... but that you can calculate from itch metrics