Poor Dimensional Accuracy printing High-Temp Resin on the 3B+

My business recently bought a 3B+ in order to start producing temperature resistant parts, to be used as inserts for Vulcanised Silicone Moulds. Unfortunately, we have had issues relating to warp when using support structures, while printing directly on the build plate yielded parts within a +/- 0.03mm tolerance.

We have followed the recommended post processing procedures for High Temp v2, including using the form wash and cure, and every time we have gotten dimensional inaccuracies ranging from 0.08 to 0.18mm, depending on the orientation.

As someone new to this field, and coming from FDM, I would never expected SLA be so finnicky that our Prusa mks3 is more accurate consistently. I designed a part with internal channels with a diameter of 2.7mm, and was unable to insert a 2.5mm rod into it. The sag is real.

Pictured here is also a different part that deviates from our CAD model by more than 0.15mm

I have never designed parts with SLA printing in mind before, but when we bought similar parts from a 3D printing service we did not have this issue.

Quite frankly, I am dissapointed with this printer. Obviously I wasn’t expecting some plug and play wonder machine that could 100% accurately make parts, but I was also not expecting for us to run into such huge warping issues. +/- 0.05 mm in the xy plane would be acceptable for us, but what we have currently is way too much.

Has anyone else noticed something similar, or run into the same problem? Did I expect too much from this machine, or did we get a defective product? Thank you for any input