If you ever want to quickly insert a freeze frame and avoid the steps involved in the use of a velocity envelope, here's a free Happy Otter Scripts tool that you may find useful. Rather than adding a velocity envelope, a lossless png is created and inserted. The default mode is to insert a freeze frame at the cursor position for the selected track. Here's a demo of of the tool where freeze frames are inserted at markers.

It may be downloaded here. https://tools4vegas.com/insert-freeze-frame/
A big thanks to Joelson Forte who collaborated on the development of this tool.