I've created several custom plugins for Paraview, along with some python macros that chain some of the filter commands together to make the user experience more friendly and efficient. It would be nice if you could enable a macro(s) to be automatically loaded into Paraview along with a plugin.

Update the render view or layout display whilst exporting animations to show the current frame.

Display the estimated time remaining when exporting animations.

Add an opportunity to change GUI language

I like the ability to create a custom viewpoint, but one can only give them names in the configure viewpoints menu. The main toolbar just shows 1, 2, 3, and so on. It would be great for those numbers to be replaced with the viewpoint name, e.g. Arctic Ocean.

I find very annoying and tedious to change fonts one by one in many different places when the same font is wanted everywhere.

For example, while producing two line charts where I didn't want to use the standard fonts I had to change the font manually 10 times (2x legend, left axis label, left axis, bottom axis label, bottom axis).

Would be thus a very nice feature to set the fonts once for all everywhere if needed.

Import georeferenced image as a flat surface in 3D or texture

Enable exporting the pipeline result to Fbx file with the color,filters and legend.

Enable customization of the 2d Gliph with a custom user's image

ParaView is a rather complicated 3d scientific visualization software. It's difficult for beginners to understand the basics from a book.
I suggest adding some basic short video tutorials to help people understand the key components of the software and include more examples (maybe the most common questions from the support forum).

.off files are great to read and write.

Reader for .dx files

add the possibility to read results from Ansys-CFX CFD code.

For those using render view for small multiples (e.g., subplots of different months of seasons of climate data), it would be nice to be able to add one super title overlying all the individual views upon export/screenshotting.

This would be similar to pyplot.suptitle in python.

Any chance we will be seeing the ability to add canned 3D scenes to a Jupyter notebook (much like the interactive plotly charts) - this would really make reports reading interesting. I think you're almost there with Paraview web!

The default cylinder aligns along y-axis. It would be much helpful, if the users can specify the orientation vector of the cylinder directly inside the paraview.