As discussed yesterday - here is what I suggest in these scenarios and a bit of background
The corridor model is designed and optimized for curvilinear alignments. While it can do a certain amount with angular corners it was never really designed to tackle them, because at a right angle corner, on the inside things disappear and on the outside things get larger, and when you compute the "sections" for a surface at intervals you have to be really careful how you model a right angle or angular corner. We currently take the node point and bisect the angle to compute the outside offset and the inside offset corners. However because the corridor is a sequential modeling engine, that models each station starting from the small station end incrementing up station, it looks at each station that it computes in isolation, and does not look ahead or backwards to see if it is creating crossovers or clashes - in the template editor, you will see that it truncates the cross sections on the inside of a curve, if the section on the inside is longer than the radius of the curve, but again that is done at each station only and not as a collective model.
When you densify a surface, it is looking for areas where you have "a lot going on" e.g. Radius or spiral sections that need to be densified to compute a smooth surface throygh curb returns, vertical alignments where vertical curves are in play, superelevations or slope changes where the slopes are changing and in widenings or changes of direction. This results in more data being computed in these areas. A right Angle corner falls into this category as well and as a result you get some strange results at right angle corners like you have seen when you densify - so I dont recommend that.
So you have two options to densify the curved corners of the wall
1) I call this the TBC equivalent of Terramodel XLINES. In the Corridor Template, create an Offset Slope or Offset Elevation Instruction. Use the alignment as the reference for the instruction. For the Offsets use a Table and in the table enter all the Stations where you would like extra drops around the curve sections of the wall. i.e. if a curve starts at station 100 and ends at 112.5 and you would like drops eg every 2' around the curve, enter the stations 102, 104, 106, 108, 110, 112 in the Station fields and enter 0 as the Offset value. For the Elevation Delta or Slope enter 0% or ) elevation Delta. For the Material Layer uncheck all of the Material Layers. Give the Node the name XLINES or similar. What this will do is to create you drops in the Corridor Surface Model at all these stations. Enter the table values for all of the curves on the wall. You can create the table in Excel and then Copy and Past it into TBC Table. This will have zero effect on the Surface result, other than create you the extra drop locations in the model.
2) As an alternative to (1) you can also use the RPS Command called Define Extra Stations - you can download and install this using TML Status. This allows you to define Extra Stations on an Alignment that are picked up by the Corridor and Sideslope command for Corridor Surface Outputs and reporting purposes. Again enter the same stations as you used in (1) above here as Extra Stations.
For the angle corners, just let the corridor pick its locations using the alignment node locations and this will improve the model in these areas.
As we found yesterday, the Show Direction and Define Extra Stations commands did not work with a HAL only alignment. If you add a dummy VAL to the HAL using a Grade Break at the start and end of the alignment and an elevation close to the elevation of the wall, they will work just fine. The Define Extra Stations issue was a defect in TBC code and that was fixed yesterday for the next release, the Show Direction we were looking at that last night and I expect an update that addresses that today.
Alan