Can FIN Framework run on a Raspberry Pi 4?

Yes, FIN can easily run on a Raspberry Pi. It would run on a 3 + and definitely on a 4. Generally, for embedded applications, we recommend at least a 1.2GHz dual core processor with 1GB RAM and 2-4GB flash. The Pi 4 is better than this. Several companies have previously ported the Linux version of FIN to Raspberry Pis. You will need to be reasonably familiar with Linux and need to load OpenJDK to provide the JVM before installing FIN. Be sure to ask for the Linux version. If you intend to use a Raspberry Pi then you should find versions intended for industrial applications and be sure to use high quality flash otherwise the read/writes lifetime may become an issue.
e.g. Kunbus Evolution Pi Meet the Revolution Pi products - Industrial Raspberry Pi (kunbus.com)