I think it would be possible to have 3 maxed in that time, maybe four — especially if you’re plugged in, know what to prepare for, maxed out, etc.
I’d be more worried about the carpal tunnel than an exploit. Your talking about a well know mechanism that compresses maybe a week (until you see many examples) to a few hours.
Totally doable. Not to mention to actually be an exploit (defined as taking advantage of a published gap) you’d need to have a LOT going on in different areas or one hell of a bug that allowed short circuiting a lot of checks and balances.
I also give no f—is if a well known top player wants to max their stuff quickly.
About the only thing I think would raise an eyebrow as a passive exploit is 5* emblems at or near max —
The flip side; is if you are concerned about something; file a ticket or post a generic question after researching. If you want credibility; earn it through demeanor and preliminary research, test what you find for scenarios — then ask for peer review and feedback.
Read Garawyn’s math posts for good examples.
No villagers, no pitchforks or torches — and no poo flinging an idea presented as an issue, calling out individuals or calls for others to do the preliminary validation.
If your concerned’ own it, develop it and ask for guidance — after reading the forum rules.
Running into stuff like this in the wild is great fun — i like to rematch 3 times personally. Maybe I’ll get lucky and get my ash handed back to me in the 3rd try loot.