Smart meters

I have a smart meter but it’s the old SMETS 1 and Bulb have just sent an email saying they are installing in my area could I change it for SMETS 2 or will this one be OK.
I used to be with British Gas years ago and was on their free time tariff then moved to Outfox the Market for 11 months but even though I moved the meter records on a different setting on Sundays between 09:00 and 17:00 and still does. I hope even with the two readings bulb are not just taking the ACT 1 reading as the ACT 2 reading is about 4 units in that free time period.