One CVE is not going to provide anything in the way of CAP coverage even if the airwing is set at 100%.
The reason is each starts out with only 10 fighters, and from that you deduct rotation to refuel / rearm, pilot fatigue, Op loss and of course having what is airborne having to cover several sectors. Take all that into consideration and you are truly blessed if 1-2 fighters find themselves in the right place and time when the waves of Bettys arrive from Truk.
Best to assemble multiple CVEs, or better yet pair them up with a fleet carrier (Wasp or a CVL) and radar equipped escorts to get the most bang for your buck.
Also, do not place the carriers in the same hex as the landing beach. CAP flying from a carrier that is parked in a shallow water hex will be reduced by 25% (IIRC). That alone is all the more reason to assemble multiple carriers to 'phib Ops - one can provide CAP to the landing zone and the other to the TF.
"splendid was their tactic of diving upon our force from the direction of the sun, taking advantage of intermittent clouds"
-Captain Takahisa Amagai, KAGA, June 4th 1942