It does depend on your situation. For us it's a no brainer. April we made money and will make money till probably October. Nov-march we've halved our electricity bills at least. I means I am more comfortable having the heating on and it offsets the cost of gas.
But we don't and won't have an electric car so that's also something to think about.
Even with the electric car taking around 300kwh in April I still ended at a negative bill of around £15 credit.
Obviously it will depend on size of install, mileage of EV etc but as far as I’m concerned flux is brilliant even as an EV owner at the mo.
Only caveat is that super short 3hr block limits me to 21kwh per night at cheap rate into the car or ~25% charge. If your commute was using more than that you’d have a bit of an issue staying topped up during the week potentially.