Net: Don't send large unreliable packets by reliable fragments
http://lists.cubik.org/pipermail/enet-discuss/2024-June/002503.html
It seems that by default ENet just wants to behave as nicely as possible, and therefore packets without flags are unreliable if they fit in the MTU, and reliable otherwise.
See also this:
https://github.com/nxrighthere/ENet-CSharp/blob/
6e3d4e48/README.md?plain=1#L229
https://github.com/insthync/ENetForUnity/blob/
bde64ed4/ENetCS/PacketFlags.cs#L30-L34
https://docs.zer7.com/enetcs/ENet~ENet.PacketFlags.html
http://lists.cubik.org/pipermail/enet-discuss/2011-June/001777.html