I kept and bred them in this tank:
Many discus folks and a few plant folks seem to think they are incompatible.
They are very mistaken. Perhaps they failed themselves due to a lack of understanding and execution? That's what I've seen, but I've had no issues issues keeping either together for a decade or more now.
Have been listening to Discus zealots again?

haha
If the goal is max sizes, max brood from breeding, where fish are the absolute primary focus, then bare tanks are good.
If the goal is having nice looking tanks with plants, nice healthy fish, then planted tanks are great.
Fish may be grown out in bare tanks and then transferred or you may raise them up in planted tanks with a little less feeding etc. Depends if you want the largest most massive fish. That's not my personal goal with any fish though.
I want them healthy, happy, and in a nice home they can live in for many years. Not 4 ugly glass walls. Same for any fish. I raise fish in nice somewhat natural environments, not cattle on a farm. But there are fish farmers trying to get the most production and size/growth out of their livestock so they give their advice, but you need to keep in mind what is your goal.
When folks say Discus and plants are not compatible?
You know they are off their rockers!
I hear this all the time on the web which is why I'm dicussing this in such terms, it's not a personal thing here directed towards you.
Discus are pretty hardy critters truth be told.
So are plants.
Most every plants can be kept at 82-84F which is about where I keep most of the SA tanks I keep and tend to.
Soft water is fine also for plants.
High light is fine, fish will hide in the plants if they are tired of it or swim under a root etc.
CO2 is fine if you also make sure the O2 is also good(they turn black/darker if the O2 drops).
Adding KNO3 is not the same as Fish waste from fish food etc, which starts out as NH4 and drains O2 levels or is used by plants directly which also adds O2 through photosynthesis.
There are other misconceptions and no Discus person to date has provided good evidence to counter the arguments I've made in the past.
I have been able to falsify each one of their claims. Thus such hypothesis must be rejected and a new alternative one is made.
Regards,
Tom Barr