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The AIDA standards say to not dive at all for the rest of the day if you have done a dive deeper than 55-60m. This includes shallow and safety dives although in my experience and opinion almost everyone would be fine doing shallow safeties (<25m) . For some this could be an overly conservative recommendation and for others who are more succepttable to DCS could save their lives. When you say work at 70 with a scooter I'm assuming there is a task to be completed requiring bottom time (i.e. Changing a mooring or something like that??) which would mean absolutely not doing that depth more than once per diver. Some people may say that it would be fine and that they've done repeats in the 70s but if you look at Will Trubridge's recent accident it would be like playing Russian roulette.
In theory it would be possible to do these dives safely by doing them on exhale and limiting N2 exposure, or by doing O2 decompressions after each dive with a very long surface interval. (We don't know enough to recommend that interval).