Fix is now in alpha zips, let me know if it works aright.
Improved, but still rather odd.
The test state here that duplicated the results shown in Vyrt's screenshots above in r208: Beginner's Tooltips disabled & Enhanced Tooltips enabled in Blizzard's Interface, Game, Help frame.
Now with r212's chatcopy.lua, mousing over a chat tab it puts what appears to be the beginner's tooltip for the chat tab (that appears normally when you have that turned on) with the BCM "help" line at the bottom:
Chat Options Right-click to get a list of customizable options for this window. Left-click and drag to move the window.
(icon) Double-click to copy chat.
You get that tooltip even when you have Beginner's Tooltips turned off, which is unexpected.
r213 works reliably regarding the scrolldown.lua module, but found out what the/a problem was. It + buttons.lua are not totally compatible with Chatter's TinyChat module.
Been using that module in that mod forever; its been around for literally years. So when BCM added that functionality in dont_disable.lua, I of course disabled it ;). Commented out lines 13 & 14 while keeping TinyChat active.
But...doing that causes random issues with BCM's scrolldown + buttons. On one raid character, there was never an issue with the scrolldown icon appearing. But on a different raid character...with a very similar (but not identical) total mod load, identical chat mod load & identical Chatter profile to the other one, BCM's scrolldown icon rarely appeared after logon. It did appear on two occasions, but on 95% of the logons with that character, it never did.
Put back BCM's chat resizing (uncommented those two lines in dont_disable.lua), disabled Chatter's TinyChat. Now the scrolldown icon appears 100% of the time on that character it was having issues on (& all other characters).
I just want to apologize to anyone using alpha, it may not be the best idea. I'm (slowly) working away at a hand-made basic gui for BCM that will hopefully make it somewhat easier to use. If you hate the idea of BCM having a config, you can type
/script bcmDB.noconfig = true
ingame, and the module simply won't load. You can also use this after you're done using the config if you wish to save a few kb. The config is a module isolated from the rest of the modules, which makes that possible.