There can be two official versions - that available on the web and that being shipped in new/serviced units direct from Meridian.

For G9x, 1.81 is also official - that is what is being shipped with new G9x and service returns. Apart from being a bug fix, 1.73 -> 1.81 added an extra HDMI info screen listing data from the EDID. I also feel that it gave better HDMI stability and recovery in error situations. I think the next version will be around 1.86 - 1.89 re HDMax functionality. I believe that it will also address some playability issues with some discs.

DSP33's is as you state 1.07 - for me the biggest change in this was to keep the units powered on rather than revert to standby. I believe this is to fix an issue whereby the speakers were reluctant to come out of standby under some circumstances. It took a while to fathom why the green light on the back stayed bright all the time and this may not please some people knowing that everything is fully powered.

FWIW I don't think it is right to report beta versions unless they are made public by Meridian - that is just my stance and I know others will have a different opinion. Other odd versions can however be spotted by eagle eyes at some dealers.

Meridian owner since 1992
Prime & PSU, Focal Elear headphones, Roon (ROCK 8Gi5 NUC), Explorer 1 & 2, F80. 200/203, various Sonos (via Roon).