reduce memory usage during checks?

[tdhock]

Hi @alexiosg ! as shown in tdhock/data.table-revdeps#40, your ts* packages use too much memory to run our checks (which include compiling your package and all dependencies, then running R CMD check—not sure which of these operations takes a lot of memory) using a 32GB limit. data.table devs would like to run these checks every day to make sure any changes on data.table github master are still compatible with your ts* packages. Could you please try to fix this in a future CRAN release of your package?

[alexiosg]

This is likely due to their dependency on the TMB package (for automatic differentiation in the C++ code). I'll investigate whether there are any options to improve this when time allows.