We have had very good results casting RP parts. We have a 3 hour dwell time at 300 degF. This seems to let everything settle down. The thermal expansion rates of investment and cured resin are very different from each other. We have seen problems with small cracks in the investment if this step is not done. That can not only show up in the casting, but bits of investment can flake off resulting in pits in the metal casting. We regularly cast small parts in stainless steels and other refractory alloys using R&R Astrovest in flask casting (not shell casting) with a highly modified centrifugal machine. We even use Astrovest for bronze/brass because we are used to it (we could use Kerr Satincast if we wanted to for these alloys). We are probably using much larger flasks than the normal user and this may account for the extended dwell time we need.
We cast steel et al at between 800 and 1200 degF depending on the section thickness. Clearly, we are not casting jewelry, but take this for what it is worth.
I have seen photos here with poor surface finish and it appears to me that the caster is not even using the brief low temperature dwell recommended by Formlabs or the part has not been properly UV postcured. Even our large parts have better surface finish than the photos.