I don't grant the premise that per-transaction urandom reads are likely a meaningful expense to begin with but on modern Linux getrandom is a vDSO anyways. Even

I don't grant the premise that per-transaction urandom reads are likely a meaningful expense to begin with but on modern Linux getrandom is a vDSO anyways. Even before the vDSO, getrandom was fast. The application domain where this tends to get brought up as a problem is in large-scale simulation. I have no opinion about whether getrandom is fast enough for simulation, but here we're talking about cryptographic random numbers, not simply high-quality random numbers. If you want to use something like PCG for your simulations I won't dunk on you.