@op why do you not want to mine segwit txs, anyway yes they won't be segwit compliment if the coinbase pays to legacy but you're also not doing much to help the network by confirming transactions if you just pass in your own.
(And when I read that my block will be considered invalid, I assume that means that if I happen solve a block, that all mining effort will have been wasted, no exception.)
In the last line of my original post (above) I assumed that if my non-SegWit compliant NOMP pool software found and submitted a non-compliant block, that the block would be determined to be invalid by SegWit-compliant nodes, thereby wasting all of my mining efforts.
Is that true?
I then assumed that I could either only include non-SegWit compliant transactions in the block or, since I wasn't too sure how many of those still existed, I would make Empty Blocks (blocks with only the coinbase transaction) since, as I read, the coinbase transaction doesn't use SegWit since there are no inputs...
...but if as Carlton (and I assume you) say, it doesn't matter (e.g., what I asked above is not true), then I can just keep doing what I'm doing.
Comment?