I agree with your assessment of TPL. I wish some interested poster here would find out which indexes TPL may be included in that do not yet hold a position. Any chance this gets added to the S&P 500? Anyone? That would be a great question for IR.
Keep in mind that as TPL's inclusion in ETF's expands so does its vulnerability to sharp selloffs when the indexes decide to reduce a position and it all occurs at the same time. If oil & natural gas prices enter into a super-cycle bull market then the upside here could be towards $4,000.