My evidence is that HTTP/2 doesn't help much if at all for lightweight sites, especially if the site manages to hit my target of the first 10kB hitting the client rendering all the above-the-fold information, and especially if the clients are reasonably close to the server.
Indeed, given that HTTP/2 forces TLS (for any mainstream browser) which forces an extra RTT, for light pages my evidence is that HTTP/2 makes things marginally worse...
Variation in page load times far outweighed any difference the config change might have brought.
So, YMMV.
From a theoretical standpoint I agree http/2 should help (although in practice I didn't measure any difference). I can't see why tcp_nodelay would help except in extremely niche applications (sending tiny responses with lots of pauses?)