I should have dealt with this a long time ago, just haven't had the time.
The only reason I haven't upgraded to version 10 is almost every time I am using Opus 9 for extended periods of time, and then move a file from one window to another in dual window mode, or just move a file from the current Lister to the directory tree, I get an error telling me I can't move the file because it is open in another application, and that application is always the x64 helper app. I use task Manager to stop the x64 helper app, and then Opus will let me move the file. This started happening just before you came out with version 10, and I first tried to update 9 in hopes this problem would have been fixed, but you didn't fix it in 9 and I won't upgrade until this behavior is fixed in 10.
So, has it been?
Yes, Opus 10 has never had/needed the x64 helper app.
I don't know why the helper app in Opus 9 would have been locking files that you were trying to move, but the app doesn't exist anymore in Opus 10 anyway.
I'm assuming you mean Opus 9's dopusx64.exe ("Directory Opus 9 x64 Helper") in the main Opus program files folder.
(On the other hand, we do still have Viewers\docsvw64.exe and Viewers\docsvw32.exe ("Directory Opus ActiveX Proxy") which can be used to view files using 3rd party viewers. If either of those are locking files then it's an issue with the 3rd party viewer but you may be able to solve it by configuring the ActiveX+Preview+Office+Web plugin to open a temp copy of the file instead of opening the file directly, or in various other ways, depending on the exact nature of the problem.)
You can grab the free trial version to check, if you want. (Backup your Opus 9 config first, in case you want to go back to it. The config will import and be converted from 9 to 10 automatically, but not in the opposite direction.)