Like in this simple subnet, if I'd like to inspect what the input looks like, what's the quickest way to do that? (I know I can put a Null, but adding a new node just to see the input is so inconvenient)

+1 for flaggable inputs!

Surprisingly you can middle click the input to see how many primitives or points it has. But to actually see what it looks like Houdini just throws up its hand ¯\_(ツ)_/¯

In your diagram, all nodes have one output, and therefore the display flag shows its value without any ambiguity. The node has three inputs, but you can view each input from the previous node, which is logical.

The problem you described applies to nodes with more than one output, but frankly, for such rare cases, it's easier to set "null" than to create extra flags that will interfere in 99% of other cases. So, I'm in favor of "null."

In your HDAs, you can easily add a "preview" button/toggle and connect a switch to output other branches to the main output and immediately see them in the display flag. I do this when I often want to view a second input, for example, masks.

I'm not sure if you're serious. Did you just write several paragraphs to explain why we don't need this little simple QoL feature...? Like, do you actively hope Houdini to not have this?

All I want is to make the input node work like a virtual Null so we can put the display flag on it without creating any "ambiguity" (whatever this means...) or "interfere" anything (whatever this means...). It's literally just to save a few click and make the network less cluttered. That's it.

Well, I'm a big fan of user-friendly interfaces and have a lot of complaints about Houdini's interface, but I don't understand your problem at all, sorry. I don't understand what the "input node" in your description means. Any node displays ITS OWN result. Do you want it to display SOMEONE ELSE'S result? That's strange. What's stopping you from clicking on the source node? I know the problem when a wire comes to your node from very far away and it's difficult to find and view the owner. But I vote for null again, because this is the wire visualizer you're looking for. It has the flag you're looking for in SOP. And in COP, it also has a preview. You can add it or not. Excellent. This is fundamentally better and more correct than cluttering up flags in one node, I'm sure.

Sry Gaalvk, but if you don't understand what the discussion is about, why do you participate?
It's about the INPUT nodes of a subnet. They are not flaggable atm. It would be great if they were.

Cheers
CYTE

While this would unambiguously be a nice Qol bump, putting down a Null is so trivial and quick and something that can be reduced to a single click, I can't see SideFX dedicating any time to this at all.