Strategy for 1'st time user of 3'rd party DAM w/ C1 - about to upgrade to v.21

Fuji user currently using C1 12 but about to upgrade to 21 and before doing so am looking to integrate a 3'rd party DAM solution into my workflow. I've never had a problem myself with using a catalog in C1, but I've read where others have and more lately where catalogs have an even greater tendency to be dodgy when updating to 20/21.

Looking for some advice on strategy.

I'm willing to start from scratch and abandon my current C1 catalog and put in the time to organize in a completely different way, if that's the best route.

Would like to get IMatch, but funds are short at the moment, so I'm settling on Digikam with the idea that I can (hopefully) painlessly change to IM in the future should I need to. My DAM needs are pretty basic - or so I'd like to think.

Generally I shoot RAW only, but sometimes RAW + JPG or JPG only if it's a snapshot - like for a photo I want to take for informational purposes only, to use for an ebay announcement, etc. I tend to export JPG's only when needed and like to keep the original RAW files should I ever decide to re-edit. I'm more concerned with managing RAW files than I am JPG's.

My thought is to continue using C1 sessions for work (interiors) related images. Anything I might want to use for my portfolio purposes can be placed in the DAM, but once I'm done with a project I can move everything I have no personal interest in to an external drive and pretty much forget about it. Any new, DAM based catalog is really mostly for personal use.

When I used keywords back when I was using Aperture I found it to be time sponge. Occasional misspelled words, using multiple variations of the same keyword, etc, made it seem like a waste of time and ineffective; my fault entirely.

I don't care about or think in terms of dates. What's worked for me and what I started with in LR (before importing that catalog into C1) is a basic folder system. For example: Country > City > (if necessary) locations within the city. Or: Nature > Trees/Flowers/Insects. My people photography is either strangers on the street or family members; nothing big enough volume wise where I need to use some sort of AI face recognition.

I'm okay with scrolling through the last folder to find what I'm looking for. If a folder gets a bit too large then I create further subfolders.

It's not so much that I'm having trouble finding my photos, it's the desire to avoid any potential catalog problems with C1 as I change versions, the catalog continues to grow, and any other potential problems. I'd like to get more organized and do it right. I'm extremely happy with C1 from how my RAW files are converted to the final output and every thing in between, but until (and if) C1 makes improvements to the DAM aspect of the software I don't want to relying on C1 for anything other than RAW conversion and editing.

I've read here, or elsewhere, a post suggesting folders no, keywords yes. When searching for photos just enter the keyword(s) and similar to how smart folders work, the DAM will show what I'm looking for. I'm game for that, esp. if I can add those keywords all at once to multiple files while using the existing folder structure to find those files. I don't mind putting the work in to better organize, but obviously I'd like to make it as fast and easy as possible.

My initial thought (which could be completely wrong or irrelevant - hence this thread) is to set up any new DAM structure before making the upgrade to C1 21 and never use my existing catalog currently within C1 - start completely fresh. I don't want to create a situation where I'd make things worse by not following a logical step-by-step method to doing this. Since this situation is new to me I don't trust in my intial thoughts/instincts enough to go down that path and would prefer to hear what others with more experience have to say.

I'm about to dive into Digikam tutorials/documentation, but notice as far as documentation that the most recent stuff is for version 5.x - nothing current. Not surprising considering it's Open Source. Being that my needs are basic I hope this shouldn't be an issue, but would be interested in knowing if there's more current documentation I haven't come across, if anyone has a recommended tutorial they can point out, or any other suggestions as far as a strategy to accomplish what I'm looking to do.

Sorry for the length and reptition of a subject touched upon before, but since there are so many different ways to go about this I figured it would be beneficial to ask with my specific needs based on my current workflow. Thanks.