I have some acacia acuminata root bark and am interested in the best extraction tek. I have a stainless pressure cooker and am considering 3 x acid boils then a reduction before basifying. Ideally I'd filter out the bark before basification for ease of handling.

Thoughts on best way to proceed with 50g bark?

Have a look on the wiki.

You're describing a standard A/B, the PC is an established add-on to the process. No need to overthink this one.

Yes a pressure cooker is the way to go. They do an excellent job at reaching all the DMT trapped within the material. I'd advise just shredding the bark as it makes it easier to remove after the acid boils in the PC. I also like to do the entire process in the PC pot. My own pressure cooker is a decent size. I believe that the large surface area helps when doing your pulls due the solvent making contact with more of the DMT. This does require transfer to a smaller container to do the pulls each time though because the solvent layer is so thin on a large surface area. Also, doing the pulls whilst it is still hot from the PCing will mean less pulls.

Here is a simple tek for a Pressure Cooker.