For example this configuration:

library(sls)
sim_pars <- start_pars <- c(0.2, 0.1, 0.6, 0.2)
sls_main(
seed = 6,
sim_pars = sim_pars,
cond = 3,
start_pars = start_pars,
verbose = TRUE,
l_2 = sim_get_standard_l_2(
crown_age = 10,
shift_time = 5
)
)

pars_m and pars_s should be collected under a unique "pars".
brts_m and brts_s have to become parts of a unique list "brts".

In the current version I can handle trees with 150 species in the mainclade. If I try with 200 the likelihood will be too smal that falls under machine precision. It is probably fine for practical purposes.

Hi @Giappo,I took a look at the new state of your code. I see you did not push the latest version yet.