I’m really surprised that GC is an issue at the bits/sec throughput a TUI would be pushing. At the risk of making an obvious observation: your render loop is doing way too much work for what it is producing.
For the GC pauses specifically, what mattered is predictable performance. More allocations == more GC == more frames where the VM is locked up seemingly doing nothing. On slower machines we were seeing this be in the order of seconds, not ms and when somebody is typing all they feel is the 1 character that's stuttering. Honestly, I was surprised about this too as GC in JS is often not something that's too impactful.
You mean like a laptop that is trying to stay cool (aka, cpu throttling) on battery power while Claude is running a slightly different version of the test suite for the 5th time to verify it didn't break anything?
Yeah, the typing latency is really bad in those cases. Sometimes waiting for 40 seconds or more.