There is no feature like that currently, but it can be added. Why do you say ‘either horizontally and vertically’? Why not both? What would control which way the image is to be stretched?
That would be the same as stretching it both ways, correct?
The option to stretch the embedded image can be added, however, it would not be a very high priority task for me, unfortunately. I believe you are the only user to request it. If you are interested in fast-tracking the development of this feature, please send me an email message to admin at maximum dot software and we can discuss it.
Alignment is actually something I planned on adding already for a while. I guess both of these features can be added at the same time. Let me think about it and see if I can allocate time/budget for it.