I was mostly curious as to why one would want both, it seems an expensive choice for minimal gain. Alibaba shows some CCS to CdM adapters. As CdM vanishes, you might see these spring up so that old Nissan cars can charge on the larger network, either to be bought by the owners or better, to be present at the CCS only charging stations for use by those drivers, and by Tesla drivers with a CdM adapter perhaps -- double adapter -- who can't use Tesla's CCS adapter.
I am a bit surprised at what they are paying on eBay for CdM adapters with the CCS coming so soon. So surprised that I sold mine at too much profit. Even for those of us with older cars that can't use the CCS, I anticipate the demand for CdM adapters will drop a lot when the CCS can be bought in the Tesla store. They always sold for a profit on eBay, which was a bit odd, largely because they kept going out of stock at the Tesla store. I contemplated buying extra when they were in stock -- would have made a fat profit -- but decided I was not in it for that.
On the other hand, for a while it was not an unreasonable thing to do, if you were going on a big road trip, to buy a CdM adapter from Tesla, do the road trip, and they sell it on eBay as nearly new for a profit. Better and negative cost compared to renting. My other plan had been to form a local "club" of Tesla owners in my neighbourhood to share the adapter, or a pool of adapters. This is the 2nd best approach to having the adapters at the stations. You only need these on road trips, and unless you take a very large number of road trips, sharing with others is high cost effective.
Note that the adapter is useful on a road trip even if you never plug it in, which is not something people realize because at first it doesn't make sense. On a road trip, you sometimes find yourself nervous, "will I make the supercharger?" You probably will make it, but you don't like the anxiety. Knowing you can stop at the DCFast station 20 miles closer than the supercharger removes the anxiety, even if, when you get there, you still have 30 miles of range left and don't need to stop.
On EVGo, while it is great that they put in the Tesla adapters, I am baffled why they put them almost entirely in cities, not too far from Superchargers, superchargers that are not filling up. Nobody is going to pick that over the supercharger which is faster, easier to use and cheaper. What they should do is identify the stations that are far from a supercharger, or near a supercharger that is regularly full. Those I might use.