Your first study is the exact same authors as the preprint you posted earlier -- these guys are really, really trying to milk their dataset to say what they think it should say.
Anyway, the figure referenced in the quote shows that 3 doses was fine (and better than 2 doses or 0 doses) against Omicron. There is no pattern of more doses = more susceptibility like you are alleging. In fact, the data makes prior infection look terrible here (against Omicron) -- it fades to uselessness so fast.
So first study doesn't support your hypothesis.
The second study was discussed plenty but again, doesn't really measure what you hope to show. The interpretation may be that boosting against WT omicron may cause some imprinting that makes one more susceptible to mild omicron infection. This is not saying that repeated boosting makes one more susceptible to COVID in general. In fact, this would suggest that boosting with a bivalent AFTER Omicron infection may be important to developed durable immunity against the new strain.
So basically, you're supporting updated boosters now? Cheers.
Regardless, the Qatar data is a little iffy because the incidence of Omicron was very small in their study. This suggests pretty tight control of spread and lots of opportunities for confounders in booster uptake and testing, etc. This has been discussed on this thread already, I believe.