FYI,So I don't know the factors determining how fast Raku can compile ("perl6 -c filename") a grammar, but:
Anecdotally I have just seen that using the surrounder syntax "left ~ right middle" rather than "left middle right" makes my 16KB MUON-defining grammar compile in 1 second rather than 6-7 seconds on my 2013 machine.
See https://github.com/muldis/Muldis_Object_Notation/commit/568713257c474ad393d2dd6777e2147432cf6ec5 for the exact diff in question that led to this speedup.
-- Darren Duncan
