It should be easy to check (I would think). Just take one screen which is crashing and convert that to use PowerTipText instead of your current NVUO approach. If that screen renders OK - then you will know that the old NVUO is the culprit - yet, the new property supports the functionality you desire/require.
The other long term benefit is that you will be Appeon Web & Appeon Mobile compliant. Now that SAP is handing the PB product over to Appeon to continue its development - I would not be surprised (just my guess) to see Appeon features appearing directly in the PB Classic IDE. 