Go the other way and buy 3mm tubing and see what it does :)
Fair enough bowden has a lot of issues like filament compression (which can’t be fixed with tubing) making it difficult to maintain a steady flow when conditions aren’t steady (e.g. acceleration and so on).
With larger diameter tubes the issue of filament compressing gets worse. In a nutshell, a larger tube diameter for “rigid” materials somewhat is similar to the effect of a softer filament/material.
3D40 at couple hundred bucks? Absolutely not. 3D40 for $50? No. 3D40 for free? Yeah. Just don’t expect much out of it.