RAW to JPG - How do I adjust image quality / size on iPad Pro?

[jimpax]

When using Lightroom or PS Express on an iPad Pro to edit RAW files (CR2 from Canon), how can I control the size / resolution / quality of an edited image when saving it to JPEG?

[selondon]

In Lightroom, at least, you only get two options when saving (to camera roll for example), Small and Maximum Available.