Yes, there is no problem to input the reset signal for a long time in most cases.
When a reset signal is generated after power on, most pins become high-impedance state.
And port functions during the reset period will be disabled.
Therefore, the through-current never flows.
On the other hand, some of the ports are not disabled during the reset period.
For example, in the case of RL78 / G13, P130 outputs low during the reset period.
Please refer to the user's manual and check if these ports cause problems on your system.