Total Commander

Currently when mass copy of files with the same name I see only few options - keep all with rename, or keep a newer ones. It can be much better, if there will be possible to keep a larger size files (when you copy lot of zero bytes and files with real content) or keep an older ones (in case you make copy from a backup and newer ones are corrupted in some way) or even add some regular expression to determine what to keep - based on date, size, name and extension, file attributes etc.

There is even a fewer choices when copy source is plugin - I can't select auto rename to keep all files, please unify copy window to all sources and destinations, if possible.

It can be much better, if there will be possible to keep a larger size files

This option is already implemented, if you are using current version of TC (9.0a).
(option number 7 at copy dialog or number 6 at overwrite dialog)

Yes, I use 9.0a
And there is still no such options when copy from plugin (for example, FS plugin that give access to non-windows filesystems), no option to keep older files, no option to set own copy rules. So there is a lot of place for improvements.