RE: Dynamics 365 Multi National implementation
In the past (pre-D365FO) we implemented them "on-prem", since the last 5 years people mostly have been implementing in the cloud, which is logical. Either way, 90% this was a single instance. Only one decided to deploy 3 regional centers (Europe, Singapore, USA) to have service windows / shutdowns by the timezone.
Up until D365FO v10 (2019) there had been no proper secondary / reporting currency. On my projects, financial consolidation was never implemented in D365FO but in external systems (e.g. Hyperion or SAP FI + SAP BW).
The Dynamics Management Reporter can be considered an external system too, but I have never heard of anybody trying to use it for consolidation in the real world. My feeling, it is mostly a marketing / pre-sales gag of Microsoft to use the MR for consolidation.
P.S. The latency issues may only come up in China where they have the infamous "Great Chinese firewall". India <-> Europe it was quite OK and responsive. USA <-> Europe performs like a charm.