To each their own.. I have used synthetics in BRAND NEW REBUILT engines from initial start up.. with NO PROBLEMS...
Oil will ALWAYS be a back and fourth thing but honestly Synthetic oils now adays are so much more advanced then they were even 5 years ago.. and as long as u are using an oil that has been tested in a rotary there is no reason why NOT to back it up..
Like I said the ELF/Total synthetic oil I sell for rotaries was DESIGNED and FORMULATED FOR ROTARY ENGINES.
Idementsu
AND
deliria Golden
the famous rotary oil is made by ELF/Total
Believe it!