I would also suggest adding an option to customize which days clients receive email reminders. For example, I have a client who would prefer to receive reminders only on Mondays and Wednesdays, since those are the days they are in the office handling administrative tasks.

Currently, daily reminders are overwhelming for them and tend to clutter their inbox. Having the flexibility to select specific reminder days would greatly improve the user experience.

In addition, there should be an option to set a customizable time for when the reminder is sent, based on the client’s preference (for example, 9:00 AM or 2:00 PM).

It would also be very helpful if these reminder settings could automatically repeat or setup on new project, so they don’t need to be reconfigured each time.

Absolutely!!! This is a must-update and should be very simple... It would even be better if you can add public holidays on a calendar where the system then treats it as "weekends" or non-working days.

It often happens that deadlines are not the last day of the month, but the last business day of the month.