In that .PML file that I attached, I could see that it accesses the SMB directory, even though it was never pinned to the folder tree):
Just the fact that the tab was left open made this request.
I hopefully made the folder tree to always be collapsed on start, and I'll see for the next days if it makes any difference. Such a little thing, but so annoying when it slows me by these few seconds everyday 
The Folder Tree panel needs to be closed entirely. (Not still there but with all branches collapsed; that wouldn't be enough to test if the tree is involved.)
Edit: Can you send us a Process Monitor log (.PML format) capturing the event shown in the screenshot? We can get a stack trace from there to see why they're being called.
Oh, I sent it to you on private message on Dec 21 2023. I'll send again to make sure.
Looks like it's getting the name and icon of the drive which is waking it up.
Try turning off:
And make sure this is set to False (which is the default):
Thank you for your time.
I unchecked the "Display localized folder names", and "custom_network_folder_icons" was already false.
Unfortunately, there's no difference. The HDD on the external NAS is still waking up when opening Opus for the first time, after some inactivity.
I learnt to live with this problem and close remote tabs before closing the Opus, this is why my replies are slower. I believe the problem might only be reproducible on certain configurations, e.g. low RAM NAS device where remote folder files list is not always in cache.
Unfortunately, I was unable to fix this issue.
Sometimes I'm still getting "An operation is taking longer than expected." and the disk(s) start spinning up. And after that the message about delayed load shows up: "This network folder has not been loaded automatically because of Preference settings. Click here to read the directory."
This makes not much sense, because clearly there's some request to the NAS before blocking it with delayed load 
It's difficult to avoid things accessing devices, including the OS itself. I've never found HDDs stay spun-down for long with Windows able to see them. Even if no software is actively looking at them, something will query the drive for something and cause it to spin up.
It's also usually bad for drive life to keep turning them on and off rather than leave them spinning, unless they are accessed very rarely. On top of the delays it causes, is it actually worth making them spin-down in the first place?
Yes, it's worth to spin them down. Some drives (especially for bigger backups) can "sleep" for a week without problems. Some drives I'm only accessing like 1 time per day to move some stuff on.
Leaving drives spinning up all the time is a waste of electricity, and it's decreasing their life span (although I'm aware of all these fake articles as if it was the other way around). Not to mention the noise, especially if they're in the bedroom. I have some of external Wd My Book HDDs for ~10 years, and they have no issues.
I know that Windows can wakeup some drives if there is "recent files" history enabled, or if editing some files using Word or other programs directly from the NAS. But in my case I only edit files locally, and manually copy over when needed (or simply using backupping programs in the background). So I'm sure that these external HDDs can sleep with no issues, because that's how it was for me for years.
So the only remaining issue is that Opus is sending some command that triggers / lists the SMB share before showing the "This network folder has not been loaded automatically..." message. It's especially confirmed by the message "An operation is taking longer than expected." that is shown before it. Normally, if Opus wasn't trying to query the NAS, then operation wouldn't be taking longer than expected.
Maybe my initial "idea" regarding this problem was correct? Maybe Opus is checking if the path is valid / still exists, before showing the "This network folder has not been loaded automatically..." message? That would be the most logical explanation.
Thinking about it now... Is it maybe possible to create some Opus script, so that on program close, it also closes all tabs from network shares specified by IP? This way, if I closed the Opus / Lister it wouldn't remember these remote tabs on next re-open. I think it would solve the issue for me, as I often re-open tabs manually 
Today, I had an inactive SMB share tab open for some hours.
At the end of the day I started closing all tabs one-by-one.
Once I clicked (misclicked) on that SMB tab (instead of the X button to close it), the external HDD started spinning up, even though Dopus displayed message: "The network folder has not been loaded automatically...".
There's clearly some bug in Dopus that sends requests to remote shares, even though their load is supposed to be blocked.
