That’s what I do for the project Placeholder backup, it is updated every 5 or 10 minutes (and we got an alert on the forum when nobody was running the software that updates the project). In this case, the trigger is new incoming observations (observations with ID higher than the highest ID previously checked by the software).
Beware that a project populated in ~real time has absolute priority over all others projects I manage, and inevitably slows down populating all the other projects. So, I populate a project in ~real time only if it is technically mandatory. In the case of the project Placeholder backup, the constraint is to pick up the species_guess data field (containing the identification placeholder) before it is overwritten by the common name (in whatever language) of an identification added by the observer themselves. And I have no way to check if the species_guess content is a placeholder from the observer or a common name originating from an ID (ID possibly deleted meanwhile), so the only solution to get a true placeholder from the species_guess is to retrieve it in ~real time.
We don’t have such a constraint for populating a project related to Mavericks, or to Pre-Mavericks.
In the case of Mavericks, the trigger for populating a project in ~real time would be new incoming identifications. That’s possible, there is a filter id_above in the API for searching identifications, so that a software would be able to check repeatedly the new incoming identifications, only those whose ID is higher than the highest ID previously checked by the software.
At the present time, we are only 2 persons running day and night the sofware populating the projects I manage, so it’s not possible to add an additional ~realtime process in the software, unless a 3rd or 4th person joins the effort for running the software day and night. The software we run is already very busy and the workload (new obervations in a day) is always increasing, but every person running the software is limited to 10,000 requests to the iNat API per day. The software is a Windows desktop application.