In response to a user request (underwritten with a donation to the cause), RSVPMaker now allows you to establish coupon codes for discount pricing for an event.

Specific pricing, such as an “Early Bird” registration offer can also have an expiration date (that’s not new).
Another feature, probably long overdue, is that you can have RSVPMaker send a “Payment Required” reminder when someone registers for your event but doesn’t pay. In e-commerce terms, this is essentially an “abandoned shopping cart” problem that needs solving if you want people to pay for an event in advance and do not want them showing up thinking they are registered when they failed to complete the registration with a payment.
This is still optional. Some groups I’ve worked with, such as professional networking organization, want people to register in advance but are fine with taking a check at the door. They offer online payment as an option, not a requirement. On the other hand, if you’re registering people for an online class, you know you have to get that payment online (no “at the door” for you).
To turn on payment reminders, go to the RSVPMaker settings screen, Payments tab.
If you want to change the notification headline or body copy from the defaults, you can do that from the Notification Templates screen under RSVP Mailer. I provide codes for including elements such as the email subject line, which are documented at the bottom of that screen.

This is also where you can customize the notification sent to the event owner and the confirmation message sent to the person registering for an event.
Limited Time Content (Updated)
The Limited Time Content wrapper block for Gutenberg has also been updated to allow the option of setting expired content to be automatically deleted. This is a container into which you can place paragraphs, images, and other content (InnerBlocks in Gutenberg terminology). You can then set a start time, an end time, or both.
The Limited Time Content block contents will be hidden if the current time is before the start time or after the end time. The idea is to allow you to display an event promotion — or any other content that only makes sense to display for a limited time, such as a limited-time price for goods or services — without worrying that it will still be showing up weeks later because you forgot to take it down.
By default, you will have to go back into the editor and remove expired content after the end date/time has passed. However, as of release 5.8.5, you can have RSVPMaker automatically delete that block of expired content.
Note: It took me several tries to find a regular expression search and replace pattern that would delete the target block and leave all other content alone. If you’re not inclined to trust the software to do this for you, you can stick with the manual method. If you use the automated method, you may want to make sure you have WordPress configured to track revisions so you can retrieve the deleted content if necessary.