Yeah - I wouldn't do JNJ - somebody asked about it.
Question: Why would the long exercise? If there is any prem. left, then it would make more sense to sell the option and buy the stock.
1 month out doesn't work. Under 2 weeks, there are some trades that look good - 20% annualized. Divs have been announced by that time, so are definite, opportunity costs are much shorter.
1 concern is getting the short synthetic too close the ex-div date - no premium left. Too far out and you have to wait for the trade to close.
I think you don’t understand the trade. There is no premium as there is no optionality. Any premium you see is an allowance for funding.