Hi, I would somehow agree to your conclusion, for one it is a lot of effort, you do not need to do this manually but of course you need to come to a conclusion about the data quality for each process, and the "derivation" of uncertainty from the data quality matrix is shaky, see the old reports on pedigree in ecoinvent at the GreenDelta website. Also, ProBas is a somewhat shaky database as well and I would not use it in a Monte Carlo simulation. I understand the need to get a feeling for the stability of your result though; maybe you can address this by sth like a cornerstone scenario or by sensitivity analyses, i.e. by changing some important input data, recalculate, and note the change in the result. That would give a range as well. Good luck!