Thanks for your feedback.

I used the version you had sent to me and what a joy: that was exactly what I needed. For testing I took something like 12k line with more files than I need and it accepted them all and opened them all!
You are doing excellent job, Martin!
God bless you!

Thanks for your suggestion.

This request has been added to the tracker:
https://winscp.net/tracker/1911

I'm sending you an email with a development version of WinSCP to the address you have used to register on this forum.

WinSCP already has this excellent feature to edit multiple files at one prompt with edit dialog
https://winscp.net/eng/docs/task_edit

You can also open an existing file this way, or even multiple files by separating their paths with semicolon (;).

But trouble is that input size of that window is limited to just 256 symbols.
This could be hardly enough for some very long full name of the file at remote side, not to mention multiple pathes of files.
I would recommend to increase it at least to 32/64K or something.
Sometime there is a need to open multiple files using full path for each.
Thank you for your great work!