http://www4.cs.fau.de/Projects/JX/

https://www.jopdesign.com

https://www.cs.cornell.edu/Info/People/chichao/sip99.pdf

https://www.azul.com/products/vega-processor/

Although I don't keep them bookmarked, I looked into my collection of real-time or embedded GC's to find these that you might feel inspired by or see as potentially useful. :)

https://www.diva-portal.org/smash/get/diva2:20899/FULLTEXT01...

http://www.vmars.tuwien.ac.at/documents/extern/3017/diss_puf...

https://researcher.watson.ibm.com/researcher/files/us-bacon/...

http://realtimegarbagecollector.com