on l2-EAD want to apply for h1 COS vs CP

[mshah1]

Hello Members

I am on L2 currently . My extension is in process . L1A got approved till feb 19 . I am planning to apply for h1 this year

question -
1. is this right time to apply or should i wait for April 18.
2. I would like maintain my EAD as long as possible to achieve this H1 with consulate processing will help ?
3. what are the drawbacks of h1 CP ?

Thanks in advance .