Field Curvature and/or Curve Nodes Control Keys
Please consider assigning some keyboard keys to manioulate a node and a field curvature pin of a drawn/circle/ellipse mask.
The node and its respective field curvature pin are quite small objects, thus, making it hard and time consuming to manipulate each of them. Only increasing the node and pin size won't eliminate the problem as dense polygonal selection adds iterations of manual work. So the manipulation of a single node should be somehow improved. I suggest adding some keyboard keys(or mouse and keyboard combinations) to engage one more hand into the manipulation.
For example, assigning additional control of a pin and a node by keyboard keys (like the ones you did for opacity or tone curve keys) would make a good change. I'd suggest, firstly, make a small improvement and assign a keyboard key to control the length of the curvature pin and, then, if possible add arrow keys to move it around the node. The same arrow keys might be assigned to control the node position on the image. Engaging a single node or a pin would activate the keyboard key control respectively.
Thank you for your continuing work on the project. I'd donate it if possible.