Unfortunately, HideMyDock only works with Spaces, not individual displays (which is what the OP is talking about). This is a limitation of macOS, so it's unlikely there will be an app or even a workaround that addresses the problem directly.
Correct me if I'm wrong (because I don't want to bother logging out to turn off the setting to check - I'm lazy). If you turn off "Displays have separate spaces" - it solves the original problem, but then if you put something in full screen mode on one display, the other displays become unusable (basically, they turn black and show nothing).
It’s a problem that’s been around since displays supported separate spaces. What you CAN do, instead of “Hunting” for the dock, is bring your mouse pointer to the bottom of the display where you WANT the dock to be, then pull it down. The dock “Should” return to there.
thats pretty much what i been doing but with very mix results, and at some point i'm convinced my mac like my 2nd screen more than my main since i find it increasingly more difficult to achieve this on my main, but yet one accidentally brush on the bottom of 2nd screen with my mouse, and woosh the dock gets bounced over.
Good grief, I forgot about that as well. I don't generally use the menubar (I'm a keyboard shortcut junkie), but I do like having the time, date, WiFi status, sound status items available on both screens. I have a 34" Ultrawide as a main screen and a 27" secondary display so I feel your pain there.
i tried playing around with it, however i dont see an option to keep my dock on one screen, did i miss something?
No, you didn't miss anything. The HiDock app doesn't really do anything the OS doesn't do... except remember the Dock settings for each display separately. But the original problem still exists.
ignoring application responses
tell application "Terminal"
activate
do script with command ¨ RETURN
"defaults write com.apple.Dock orientation -string bottom;killall Dock"
end tell
end ignoring