I dont recall a thread about the file transfer blocking issue so Ill go ahead and make it out.
A well seen feature to Plus! would be the disable the file transfer blocking feature of Messenger. IT IS VERY ANNOYING. Its possible hard to do because (AFAIK) there arent even patches that remove it but its just a suggestion that doesnt hurt anyone
I presume you mean the transfer of such extension as .php (and maybe .zip/.rar, but i dunno if that was removed)
That was blocked for secruity reason since there were viruses depending on you opening a file to active the virus. (the virus was giving out links/file transfers with potentially harmful contents.)