We strongly advise our user to NOT update their phone ROM version via SP Flash Tool.
Because SP Flash tool is an application to be used in fixing extreme cases of a bricked MTK Android ONLY. (Like the phone not power on at all or not booting into recovery mode...)Using SP Flash Tool require some advance knowledge which if not well applied may result in bricking or damage your phone.
Please wait your OTA update to be available in your region.
However if you are in a current Rom which does get any OTA Updates, then you can flash your phone to a Rom which have OTA Support.
You should always use the latest version of SP Flash tool.
Even you are used to SP flash tool its not recommend to flash your phone each time for an upgrade.
If you still want too,then ofcourse you can but on your OWN RISK.