BS”D
We have no idea what the families want. All well and good that it is a zechus for the niftar but there are living relatives who may not understand or appreciate this. When you go to a levaya that is not public, it looks like you are trying to make a show of yourself and your own imagined tzidkus.
And no, I do not go to levayas of anyone I do not know – that includes tzadikim. I did not go to the levaya of either the past Satmar Rov or the Pnei Menachem although I was less than 10 minutes away at the time of both levayas. All I would have done is contributed to crowd control issues or, worse yet, been tempted to look for friends in the crowds.