chacha8 (chacha20 but with fewer rounds) seeded with either a deterministic seed or from /dev/urandom (depending on what you need) is a perfectly fine PRNG, and

chacha8 (chacha20 but with fewer rounds) seeded with either a deterministic seed or from /dev/urandom (depending on what you need) is a perfectly fine PRNG, and should run at 4 GB/sec on a single core, which is plenty. Only 7 rounds of chacha are cryptographically broken, so chacha20 has excessive security margin. Using 8 rounds of that everywhere you use random today (and not a CSPRING) should be a no-brainer, I guess. On hardware with AESNI (like all x86 for the last 10 years), a reduced round AES-CTR should be very fast and also string enough for the cases when you don't need a CSPRING. Full AES-128 outputs 4.7GB/sec on my laptop, recent chips have better AES throughput.