If I transfer cryptocurrency to another exchange, it is not a taxable event, but can I choose to treat is as one?

E.g. I transfer BTC with a basis of $500 from 20 different transactions from exchange A to exchange B. The value at the time is $700.  Can I treat this as a $200 capital gain sale, plus purchasing a new single lot for $700?

Why? It can keep things simple when it comes to computing your gains in the context of all the exchanges from a specific exchange.