Yes there are options for what you ask but they might be limited and no do exactly what you have specified:
ezcell wrote:Let's say I want this form to show up only for the first 100 submissions / month, regardless of IP address
If you don't want to limit by IP, don't use that option....
ezcell wrote:Let's say I want this form to show up only for the first 100 submissions / month
The limit by numbers is simply to limit the number of submissions, not based on a monthly quota. If you set it to 100, then that's how many entries the form will accept.
ezcell wrote:.....then come back again the next month.
The automatic schedule allows for the form activation between specified dates, but it's not a recurring setting for each month - that would need you to set the following month manually (altering the Form properties for the next month). Perhaps some automation can be implemented here (not through Machform) but by writing a PHP script that updates the MF database, and run it through a CRON job, scheduled, e.g. for the day after the form expires, so its ready for the following month.