`predplot` of identified state-space system emits a warning about transfer functions

[ghost]

Hi,

It may be not a bug but using predplot on an identified state-space system with a large enough prediction horizon h results in the following warning (h=30 with a state space system of nx=6 states):

┌ Warning: High-order transfer functions are highly sensitive to numerical errors. The result may be inaccurate. Consider making use of statespace systems instead
└ @ ControlSystemsBase ~/.julia/packages/ControlSystemsBase/hoyMe/src/types/SisoTfTypes/SisoRational.jl:12

I'm trying to understand why the state-space system (identified using subspaceid) is first converted into a transfer function. I'm also not sure why high h values leads to high order transfer functions even if the order of the original system was quite low.

Thanks for your help.