Given the recent improvements to mpremote I thought I'd throw in some user feedback.

I have a project comprising ~112 Python files. These are organised in Python packages with nested subdirectories. Formerly I developed using a modified version of rshell, using rsync and per-project text macros to ensure that the target was always running current code.

With mpremote I mount the project root directory on the PC so there is no issue of synchronisation. Now that paste mode works I can use mpremote for almost everything. As a development tool it is superb :)

Alas rshell remains the quickest way to develop on platforms where the USB link is slow. Synchronising files on the target and running the application can be substantially quicker than running a large application from a mounted PC directory. This is because the amount of USB transfer is typically much reduced.

An rsync command, combined with simple per-project Bash scripts, would provide all the functionality of rshell with macros.

Note that rshell uses timestamps to do synchronisation: it ensures that this works by synchronising the target's clock to the PC's when rshell connects.