I've never restarted ours since August 2023 when it was installed. I only switch the grid on with pathetic weather (no more than 10 days a year).
The dickheads have been out to audit us several times asking if we have power. lol. Not really a lol sadly, we pay R1400 per month before we actually use any of their power, the winner is not me/us.
With solar assistant and a standard geyserwise when I push it's on button and return to my PC it already reflects (so say less than 10 seconds). What kind of lag are you talking about?