Arrghh, the ol' crusties are out in force!
Check your terminology - SAF relates to the use of existing feedstocks (domestic waste etc) to produce so-called drop-in fuels for aviation. e-fuels (or whatever - there are many terms in use) relate to technologies to convert atmospheric CO2 in hydrocarbons using renewable energy, a much longer term and way trickier prospect.
There's been loads of articles about the former in Flight in you're interested.