OK, as mentioned in the previous post I fixed several issues mostly related when the tabs are right-aligned.
But when I'm testing and changing properties I find some other issues, just for example: for client area, the top have to consider the FlatBodySeparationLineHeight to start the client area (the ClientTop for top aligned TabOrientations). It is not taking that into accout now. It is just an example.

For the TDI Forms mode I'll have to make a Region for the PictureBox containing the forms, so the rounded corners show well.

For the issue that RightToLeft is not supported for bottom TabOrientations, it is because I handle the bottom orientation in a special way. But I have an idea to fix that, that will involve changing how the bottom orientations are handled.

These things I guess they could take a couple of more days.

But... I'm thinking in changing how the TDI Mode Forms handle icons. Because it actually shows two icons, one is the X to close the tabs and I added another icon for the forms icons.
I'm thinking in completely change that, making a Closable property that could be used for all the tabs, not just the TDI mode, not using the normal icon for the X. And then for the TDI mode use that feature, not having a custom icon anymore but using the normal icons.
That is a big change, and could take more time.

I'm currently busy working in a program that I have to finish I hope in a couple of months.
So... I can't spend so many days now on this control. It is fun for me, I enjoy working on this control, but maybe I'll have to do it in free time or when I'm tired of working in the other program. Then it could take longer.

Also the TDI MOde is limited to Top and Bottom orientations, but why? If everything is fine and when structured it should also work in any TabOrientation (we'll see, I don't remember now what what the problem with that that lead me to put that limitation)

So, if you need some fix soon, I could do just that now, but maybe what you need involves things that will take more time, like fully fixing RightToLeft.

I can share the OCX with the current fixes if you want, but I think I only fixed one of the several issues that you posted.
I'll keep working now a bit more I guess, but I won't be able to fix them all right now because I can't delay the other program's work a week or so that maybe all these fixes will take.