Bull, eventually the companies that made the popular british twins routed the breather to a fitting on the top of the oil tank , and the oil tank had a second fitting on it that was the system breather.
Often a later oil tank with this factory modification can be retrofitted, or the current oil tank can be competently modified by adding the necessary features and fittings so your bike captures and re-uses the oil it spits out it's crankcase breather.
If you take your time and research this, and find a first-rate fabricator it can be done so that it is not even noticeable, and it will simply make your bike more practical and attractive to you and future owners.
My current road bike had such a primitive breather system and luckily it's manufacturer added a breather "tower" to their oil tanks later in the very manufacturing year my bike was made, so it was very easy for me to swap in the improved oil tank, just as it was very easy for me to make a few small changes to the electrical system and end up with 12V electrics, a better charging system and brighter lights. All of which are easily changed back to standard by whoever feels the need in the future.
