No, because road mapping always highlights various issues. Not just main fuel/spark tables. It can be idle, transients, boost control, knock control, lambda settings, sorting any speed/gear calibrations etc

There is no reason to lock anything if the software is done properly.

Again, I refer back back to the Simtek/Alcatek ecu's for Subarus, as it's one I'm familiar with. It's a budget ecu, but IMO the user interface is superb. It doesnt look all flashy, doesnt have lots of stupid windows or colours, but it is very easy to use either static or on the move.
Syvecs is very similar, although obviously more options and menus because it is a more featured ecu.

I would look to those two as a benchmark for good functional tuning software ( out of systems I have used )

Standard tuning changes as per the above or Motec are a simple as

+/- to change a cell. Motec uses PgUp and PgDown for the same effect. ( or use one for small increments or another for large )

Simple Shift + cursors to highlight a block of cells and either +/- them or perform a maths function ( M to open a menu ). That could be anything from +, -, x, / or interpolate vertically or horizontally.

A cell trace lock. Again a great feature for live tuning. The cursor follows load at all times, you just +/- to change values as you drive.
Ghost trace. Again, that locked cell trace simply highlights via colour the cells you just passed through. On fast cars this speeds up tuning and fine tuning boost control. As you can see clearly exactly what sites you just hit.

In addition, if knock detection is present...I'd like a feature that marks a cell where potential knock was detected. Just change the cell red for example. It may be real or false...but again it easily warns the user there may be an issue in that area ( Havent seen this feature on any ecu )

All the above is just to make live tuning faster. Yes you can revert to logs and other stuff, but that's slower for live tuning.

As mentioned before, a lambda log and potential correction table is another great feature, and would be similar to that ghost trace. Again this table would just mirror your fuel load table. You can then decided if the numbers made sense and apply automated corrections, or jut correct the main map yourself and clear the logged values for another pull.
My own DTA ecu does this and is a handy feature. The PFC Datalogit did something along those lines too.

And of course then, big screen warnings for stuff like coolant temperature or other user defined items. Sometimes when concentrating elsewhere, it's easy to miss water temp rising a little.