Co-Author here. As long as you have trust in the underlying API of the Pulumi resources that Stelvio creates on your behalf, we have a mechanism in place that let's you fine-tune every parameter if you like. See: https://stelvio.dev/concepts/customization/
Otherwise, you can stick with Stelvio's sensible defaults if you wish.
You know you aren’t making a great case for yourself right? This is a solution looking for a problem.
We believe that we're creating a solution for problems that we fought with during a combined 40 years of experience in the team. ymmv, but you are invited to give it a try. Happy to show you a demo ;)
Yet I have never had those problems in 8 years of working with AWS including almost 4 working at AWS ProServe (no longer there). I would never depend on a third party IAC package aside from Terraform knowing the surface area of AWS services and nit knowing if this is still going to be supported a decade from now.