@phrank Out of curiosity, what DAM features are you looking for that are in Lightroom and Capture One that aren't in PM+?
I can list some:
No smart folders, you can save searches in PM, but this doesn't offer the organisational structure that smart folders do
Cannot search or filter on vertical/horizontal images, often a key tool in searching (in fact I have PM auto add a "horizontal" or "vertical" keyword based on the exif tag that works.
Cannot compare more than two images at the same time (again you can sort of work around this by using large thumbnails, but comparing 4 images at a time (especially in C1) I find particularly useful.
Cannot adjust exposure of an image to allow easier comparisons between underexposed/overexposed images when culling.
Cannot have non-exporting keywords. Both C1 and LR give you a way of using "working or private" keywords in the keyword field that won't be exported when embedding keywords in a Tiff or Jpeg. This allows you to use keywords as an organisational tool e.g. "needs further editing" "possible for project x" etc.
Cannot stack images (neither can C1, but LR can) This allows stacking of images so only a top image of a stack is displayed in the browser. e.g a series of exposure bracketed files, a series of files for a pano, or images from the same burst of wildlife or sports images.
This is my personal list, and they are all things that are preventing me from fully commiting to PM+ as a DAM even though I suspect I have been using PM for maybe 20 years now, and a very committed user of PM for ingesting and keywording.