Just as a short update: Somebody contacted me via private message and suggested to use the furrr-package
which is based on futures (Bengtsson 2021); thanks for this tip! From my understanding of the paper: As there are multiple ways of doing parallelization (which partly depend on the OS), developers are advised to not implement a particular parallelization solution into their packages / functions:
"A developer who wishes to support multiple parallel backends has to implement support for each of [the end-user's options among parallel frameworks] individually and provide the end-user with a mechanism to choose between them. This approach often results in unwieldy, hard-to-maintain code of conditional statements with low test coverage" (Bengtsson 2021:274). Therefore, I do not expect the tidyLPA developers to implement parallel processing as requested one month ago. Rather, I'll be looking into finding a way of modifying the tidyLPA-function on my own in the upcoming weeks.