My strong opinion is, that the flexibility of Operaton is one of its major strengths. Camunda recommended the standalone engine / external task pattern heavily in the recent years, but its main purpose was to prepare customers for a C8 migration.
As the different architectural styles have different strengths, I would be very hesitant to recommend any of them as the default, as it might raise the impression, that it performs worse in other settings, when it’s just a matter of
Do you need transactional services?
Do you need to integrate different languages?
How does your load and processing power look like?
I agree that the flexibility is a core strength. When I first came in touch with C7, I liked the ease to integrate this into SpringBoot. But thinking more about that I thought that external tasks are powerful to orchestrate processes with a central engine and low-code. So both are totally valid.
So I would like to target also both: I would like to have show cases which allow easy scaffolding of applications and services on the one hand, and maybe on the other hand having a Operaton instance running on a cloud provider where users could deploy a (limited) number of processes and interact with external services via REST or messages.