@chrisbirdsall: It’s never a bad time to do some rebuilding, reorganizing, etc. 
Another enthusiastic vote for Dark Mode support here.
I do lots of work at night and this is becoming an issue. I understand you have a roadmap, but I would urge you to imagine those of us working in Dark Mode cringing every time they launch the app and even stopping to ask “do I really need to open DEVONthink right now?” Because it is absolutely that jarring. Sorry, but it is. That’s the UX at this point.
Can’t imagine that’s what you want.
All of this.
+1 for user interface upgrade. I also believe substance over form, but if we can have both, why not? For previous comment about Scrivener, I have to disagree that version 3 hasn’t improved upon user interface. In fact, the latest version has the dark mode enabled, and the interface looks much better than the original version of Scrivener.
I get the dichotomy between “substance and form”, but to me, the best hardware and software transcend that distinction. The form enables and empowers the substance.
As has been said above, the substance of DTPO is world class. The form leads many of us to under-utilize the app. Good design makes me WANT to use the product. DTPO’s form makes me avoid it until I have no choice but to have to use it.
Register for +1 for a Better UX. The current UI is awful. Please consider this as your high priority. Delivering great software for your customers’ satisfaction is important.
The UI needs a rework anyway so now would be the best time to implement dark mode before someone writes an AI plugin for finder ;-p
An AI plugin for finder is not that easy to implement 
for it’s not easy to integrate an AI model with apple’s file system. That will be a giant project if you’re going to make one.
BTW, DEVONthink is more than an “AI plugin for finder”. Instead, the AI feature is something I rarely use in daily tasks, for it’s not precise enough and all my files are arranged properly so I don’t need an agent to find data for me.
I’ve used DTPO for nearly two years but I think the UI is … just fine. It’s not like many recently released apps, for example Agenda.app, or anything else, but the interface clearly shows up what’s necessary. A fancier look is better, if it doesn’t bring us with heavy GUI rendering overhead.
P.S. While I think DTPO’s UI is just okay, I do feel the UI of DEVONagent is just ugly. It looks purely as outdated as OSX 10.9. Each time I’m using DA, I feel myself using a software from last century 
I’ve used DT for years and just recently switched to Mojave. Dark mode has been a pleasant surprise and I can feel a relief in my eyes after looking at so much white for so long. A switch to some sort of dark mode for DT would be a welcome addition (along with a UI refresh).
But when thinking about refreshing, please do not take the route than many apps seem to be taking where the UI gets lots of useless padding between elements a la Material Design. I would take the current UI any day over the look of spacey, non-hierarchic design.
We march to our own drummer. Changes are coming, including support for the dark mode color scheme, but it’s not going to look like an iOS app. 