With your permission OneRingRules I would like to change things up a bit...

I no longer think a saved indicator is a good idea. I would rather do a simple overlay-based alert that you dismiss by clicking okay. Because:
1) Less code / time
2) Less theme complexity overhead
3) Clearer to the user

If you're okay with that I will throw in #1802 with your sponsorship :).

I should also note that this feature can't be perfect, notably fields that were put there interactively via JavaScript (e.g. multi-input widgets), or file selections, cannot be restored. It's about preserving the primary typed text more than perfectly restoring the form you were at.

I think anything is better than going 20 minutes and loosing your post.I don't think any user interaction is worthwhile or required. It should just auto-save and maybe if anything the usual hourglass or some circle that rotates "saving" if no time constraint.

I was unsure of what you would save locally as opposed to server side in job 0001802 but happy to go with your advice regardless.

Already it should have been doing that (this issue was just for a manual force to the saving). However I've made a huge array of improvements today, around effectiveness and performance.
It now:
1) loads/saves all fields in one go rather than individual requests.
2) uses fewer cookies (one per screen instead of one per field)
3) has explicit "force save" keypress, which saves all fields right away, and tells the user how the draft feature works (builds understanding and peace of mind)
4) remote saving is now more stable
5) works on a larger set of forms
6) works on a larger variety of field types (list boxes etc)

The advantage of local saving is that it works when you're offline or the server is offline. Also, it is faster because no load/save network requests are required. This is now implemented.

The advantage of remote saving is you can switch machines.

Both saving methods always run.