but if you have no bullish outlook you’d be better of waiting for rising option prices of the put with falling price of the underlying…
btw: if you really only use the option to buy the underlying, then you should buy/sell them close or at expiry date.
however, i would not expect FIDLEG to prevent the trade of us etfs (or can you point me to a reliable source for this?). it is more likely in my opinion, that merely active solicitation will be limited.