The 'issue' for most Mac Home Users is that they would likely need access to at least two relatively modern Mac Systems/Laptops to be High Sierra beta-testers; or be prepared to reformat their 'high-end' Mac's to dual-boot both Operating Systems, as beta-OS Testing is not appropriate for live (production) use. This is only really for those who enjoy 'living on the edge'; and have sufficient time and inclination to identify, diagnose and report issues to both Apple and individual software developers.
In my opinion it would be somewhat pointless simply testing the RootsMagic for Mac download on High Sierra beta without the ability to also build and test a self-install on WINE, Crossover, PlayOnMac, Wineskin etc. to assist with diagnosing what the cause of any issues might be; and, as RootsMagic and its Windows dependencies haven't changed, any functional issues are most probably in the actual process of building the Crossover WINE application to run on MacOS.
I'm not MacOS beta testing myself as I can't afford the spare Mac hardware, time or effort required by constant 4.5Gb downloads and (re-)installations every time a new OS update is released. I went through enough of that with the early Windows 10 Insider programme; and that was much simpler. as it was (and still is) possible to install and run the OS relatively quickly as a Virtual Machine on most hardware. Not so with MacOS!