My goal is to have a numeric field that validates as the user types, but it seems that validation only runs after the user leaves the cell. Is it is possible to start cell validation when the user types, and continue refresh it again as the user continues to type or edit the field. In the example below from v4.9 examples I have edited a numeric field and then left the cell once, which correctly gives an error.
But if I renter the cell and correct it to a positive number without letters, it will still show the red validation border while editing until I leave the cell.

1. What I would like is to have the validation re-run on each character edit, so the border color will then update as you edit, and the user will know the value can be accepted before leaving the cell.
2. I would also like to prevent any entry into the cell other than a decimal number (ie. only one decimal point and only numeric characters so that the letter e can never appear in the cell), but have not found the answer yet. The numeric format appears to be for integers and shows step arrows at end, so not suitable for numbers with 1 or 2 decimal places.

Can anyone point me in the right directions?