Writing a good tube emulation that also runs on ARM, is hard.
zam-tube sounds nice and does most things right, but it’s unreasonable for the case at hand. It can even take powerful intel CPUs to the limit.
Perhaps https://github.com/sadko4u/lsp-dsp-lib will one day have something appropriate that can be re-used. Sadko does write custom ARM asm code to optimize performance.