It is a "must make" film and as such it is important that it is made - that the word gets out there. And... importance can be synonymous with quality - but only to a certain level. Documentaries can, to a large extent, be valued more on the message they convey than their artistic merit.
Sitting Limbo hovers between two genres; the informative and the artistic - as do many other "life story films". The genre is problematic as the end result is; either likely to be accused of diverging from facts under the "artistic licence" OR being true to history and respecting the facts to the point dullness.
Sitting in Limbo certainly edges toward the documentary format - it, unfortunately has not hit the sweet spot in the middle ground. And so recommendations become dependent on preference of style:
If you consider facts superior in importance to dramaturgy - chances are you will appreciate Stella Cor.radio's work. If, on the other hand, you value artistic accomplishments above facts - chances are you will feel Sitting in Limbo runs a little dry.
There is one argument which would make the above redundant, that is; IF the pacing of the film was an artists attempt to lure the viewer into similar frustration as that of our protagonist. If the "why is nothing happening" frustration is actually part of a greater master plan. If so, the greatness is likely to be appreciated by few - but would motivate some very high scoring. In any event - be prepared to feel frustration.
