If you want to explore this in yourself consider getting a continuous logging SpO2 sensor. Wellue makes good ones, I had good luck using an O2Ring to understand my own obstructive sleep apnea. It logs your blood oxygen saturation every couple of seconds and is easy to export data from.
Note fast sampling is important. Most SpO2 sensors are designed to give a reading once every 30 seconds or so, at the best. They tend to average the sample taken over that time. You want to catch the momentary dips between breaths. (For instance I don't think the Apple Watch blood oxygen sensor can do this.)
Maybe I'm wrong (not a doctor), but I believe it is very unlikely that one off events of apnea lower your saturation to a level of clinical relevance to need 2s frequency; saturation drops only after a continued chain of such events or some sort of constant obstruction (COPD, asthma exacerbation, etc).
Also, though sample of n = 1, training for freediving my breath holding PR is 3m31s, and my SpO2 barely went down. The CO2 reflex kicks in before O2 goes significantly low.
In my experience with the O2ring missing a breath or three isn't really noticeable. but I was experiencing prolonged periods of obstructive sleep apnea and it was very visible on the SpO2 graph, I could see every (infrequent) breath.
Not clear from the article how serious "screen apnea" might be; the health threat it identifies is just the stress of it, not oxygen deprivation.
You're correct re: Apple Watch O2 sensor: it takes 15 seconds to generate a result AFTER you tap the icon. No continuous sensing. True, you can repeat the sequence ad infinitum but not only does that get old fast, but it also yields simply a graph of results reported every 15 seconds with inadvertent movement artifact hardwired in as opposed to a continuous trace.
Note fast sampling is important. Most SpO2 sensors are designed to give a reading once every 30 seconds or so, at the best. They tend to average the sample taken over that time. You want to catch the momentary dips between breaths. (For instance I don't think the Apple Watch blood oxygen sensor can do this.)