I think it comes down to what a modeller can live with as far as details on the barrel. I completely understand the approach taken in casting larger parts and the trade off for accuracy.
In Dan Hay's image of a Canadian Leopard C2 from Prime Portal one can see the large single piece upper and lower thermal jackets. There is only the horizontal overlapping seam between the upper and lower halves and a smooth transition between the wider portions. Whether tape or foil or another approach is taken the horizontal seam is a detail that should flow through the entire component.
This is not a fatal flaw in the Leopard Workshop barrel but simply a detail that modellers should be aware of so they can choose how to or not to tackle it.
The clamps attaching the Base Unit to the mantlet are a similar issue. I understand the approach to not include PE parts. Very admirable with respect to keeping costs down. But, it is still a detail that is visible and missing.
Again, not a fatal flaw hence the overall 90% review rating a thumbs up recommendation for this product.
Another detailed view of a Leopard C1 barrel taken by Day Hay on Prime Portal.