ok not many then, see if the MEF drop rate changes for you as you collect more i.e. 15+
I've just got one, but its taken me 7 large +++ sites with medium security to get there. Yes it could be RNG and mean average working against me I'm wondering if its because I have more MEF stored than you though and some anti-hoarding factor at play like the rare commodities.
That would be an incorrect assertion .... i simply haven't been SEEKING MEF for well over a month or more ..... i had a stockpile that i'd gathered pre 2.2 because of new engineering mods i wanted to be ready for.
I went out last night and visited 3 bases and got 1 drop of MEF and 3 drops of CIF .... i'll head out tonight and hit up another 5 or 6 systems and report back but for me the drop rate was pretty variable