Hi Pedro, are you from Brasil? I'm from SP and as an architect I've been using drones for topography for some time now. I know of 3 SWs that currently do 3D orthorectified modeling (that I'm aware of, that is...) but I'd say only 2 of them offer good or satisfactory results IMHO. And that also depends on the project, sometimes it's not practical or accurate, not in the sense of precision but usability in some projects.
Pix4D is one of them and are on the verge of releasing a P3 compatible app but for the time being we're stuck with the other models they run on, like the 2 and V+ if we're talking about DJI. But you have to be careful with the cam/lens used, that's why I'm eagerly awaiting for the P3 app. They had a beta running some time ago, I wasn't able to qualify but I guess it's already in fine tuning stage for final release. They're pretty cool you can contact them anytime.
What I do with Pix4D is data collection for 2 or 3 projects and then grab a 1-month lease to run the batch. That's good if you want to split the lease cost among 2 or 3 clients/jobs, but I acknowledge it's not always possible as demand varies.
Either way, most clients at this point are hiring us for the novelty and to experiment with new tech and/or to stay ahead more than anything, like to showcase to investors and potential clients, stuff like that. IMHO it's advancing fast and will soon be 100% but for now I still have to rely on old tech for accurate topo at times!