Is there a way to manually edit the order that project appear in the portfolio? It is widely considered a very important part of portfolio presentation to be able to put the strongest work at the front and end, so it is critical to have control of the order.
Apologies but there is not direct way to order the portfolio items shown using the portfolio visual composer element.
You can try and use the post grid. Set it to pull from portfolio items types in the settings - data source. Then you can add a custom field in the portfolio item that then can be used to order the items on the grid.
Set the custom field in the custom field section on the portfolio edit page and make the value a number. The key should be a full word with no spaces between.
Then on the post grid settings data settings tab set order by meta value number. In meta key set the key custom field you set on the portfolio item and save.
The grid should show the portfolio items depending on the value of the meta key in the custom fields area.Hope you can implement that as an alternative.