If you wanted to treat the room (roomEQs do fantastic jobs IMO), get some GIK walnut or oak panels. They have ones which have a diffusor panel which still gives some natural reverb and doesn't deadn the sound.
I have about 8 GIK panels in my room, and 15 ceiling panels by the time I'm finished.
Ultimately with the panels, more is better so just get as many as you can get whilst it being cost efficient and still looking nice. Get them on ebay - GIK sell them loads for seconds/clearance.
Your ceiling reflections, I'd make some very thin panels to go inbetween the beams. but I reckon you won't need them as your floor is treated.
Before exploring room treatment though - I'd think carefully if you even want to go down that road. The room looks fantastic and you have plenty of lovely soft furnishings. The floor is well treated and as you live and decorate the room more over the years, you may end up naturally treating it anyway.
Room EQ is quite good - especially DIRAC - IMO for dealing with controlling bass etc and taming higher end frequencies.
Curtains to reduce reflections from the patio doors
Carpet for that hard floor
Your sofas will help also
what benefit have you seen with curtains? I've used curtains in my room and with measurements, they provided very little benefit. Proper panels IMO are the much better investment. Curtains are great for visual room treatment (e.g. blackvelvet/MVEL22/devore curtains) but for audio specifically, I find they're more snake oil than anything else. Very similar to curtaisn marketted to noise reduction for people who live on a busy road - not going tomake much difference compared to triple/quad glazing or proper sealing of the window or a wall.