Is there a free trial available for the ARM64 SaaS plans?
Yes. Genymotion SaaS trial requests include arm64 plans, and the trial limits depend on whether you choose Individual or Enterprise. See the trial flow in How do I get the free trial for Genymotion SaaS Cloud?.
Individual trials give 60 free minutes and up to 2 simultaneous devices. Enterprise trials give 1000 free minutes and up to 10 simultaneous devices, and the request is reviewed by sales.