MARS regression - num_terms


Regarding MARS regression in R I built this modelling pipeline:

mars_model <- 
  mars(num_terms = tune(), 
       prod_degree = tune(), 
       prune_method = tune()) %>%
  set_engine("earth") %>%

mars_workflow <- workflow() %>% 
  add_recipe(preprocessing) %>% 

mars_grid <- mars_workflow %>% 
  parameters() %>% 
  grid_regular(levels = 5)

When looking into the mars_grid, the parameter "num_terms" is limited to a maximum value of 5.
Even when I create a grid with a manual range (num_terms = 2L:100L)... and I have a hard time to figure out why it is limited? (I have almost 40 features in my dataset).

Best, Chris