Performance issues when plotting userscript topics from live data

[rg-gravis]

Foxglove studio uses very large amounts of CPU when plotting userscript topics live. On a Lenovo P1 Gen 6 (13th Gen Intel Core i9-13900H) running Ubuntu 20.04, Foxglove studio uses 2.5 to 3.5 cores for local or cloud data, and 5 to 6.5 for live data, with the same data and layout. Memory usage stays consistent between sources, at about 1.4-1.6 GiB. When not plotting a userscript topic, the CPU usage is between 1 to 2.5 cores, for any data source.
The script is attached here, /joint_commands is published at 100 Hz and /joint_states is published at about 1000 Hz, and the length of both iterated arrays is 6.
I am on Foxglove Studio version 2.19.1.

[jtbandes]

Internal tracking issue: https://linear.app/foxglove/issue/FG-10047