Flush / wall-aligned interior doors - experiences?

My favorite for flush doors is Linvisible from Italy. Really not cheap. But as a hidden accent in a room, a knockout.

The door is only flush on one side; if the door opening direction doesn't fit, it looks stupid.

That works too. But then the door must be reverse opening. Unfortunately, that's even more expensive. We bought all doors as reverse opening including wall-flush baseboards.

A lot is possible...
Flush on both sides with an optically continuous skirting board, with wall-identical surface on both sides, invisible due to the inner frame, opening on both sides, minimal gaps with special top and bottom stops instead of side stops, internal tensioning against warping and magnetic door catches. You’re in for €8,000-10,000. Now add fitting-free sensors and motor drive, all discreetly integrated into a fantastic wall covering made of high-quality textile on a feature wall. Now it’s 20+x...
We have spent a lot of time with this gimmick because we had the idea to optically create a doorless living space downstairs. Now we have a glass door, opening on one side in an oak frame, with a crazy handle attached. How quickly €18,000 are “saved”!

Okay, that makes me curious how that works. You can definitely do it with pictures

How quickly €18,000 are "saved"!

The best sentence of the day.

I don't want to post other people's pictures. Anyone searching for Filo 10 linvisible will find pictures. We had taken a closer look at those.

What providers for flush interior doors with hidden frames with a good price-performance ratio can you recommend?