TL;DR; 2-4x CPU and 4-5x RAM reductions!
Some time went by, and we tested it both locally and in CI. Then we rolled it out to our pre-production, and finally production environments. Here are the results with some screenshots.
On pre-production (not much traffic, occasional peaks; e.g., migrations), we see a drop from ~1.2% CPU to ~0.3% CPU and much more stable performance. RAM-wise, drop from ~2% to 0.4%. All of that is on a 0.25CPU/0.5GB RAM AWS Fargate container.
On production (lots of traffic, regular peaks; e.g., cron jobs and migrations), we see no CPU change and significant RAM reduction (1.8% → 0.8%). But there’s a twist – we scaled down the instance by a factor of two! (It was on a 0.5CPU/1GB RAM AWS Fargate container; now it’s 0.25CPU/0.5GB RAM.) So it effectively halved the CPU usage and dropped the RAM requirements 4 times.
Remember: your mileage may vary!