We purchased our first Cali in 2015 complete with new Thetford 335 cube toilet which we agreed would only be used as a last resort. We sold the toilet recently still mint and boxed having never once been tempted to use it.
For us at least, it proved to be unnecessary. You are never far from a toilet. If you do get caught short then why not get yourself one of these:
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They take up less room. You don't need to be pregnant just the owner. DO NOT attempt to use one that's in official use whether pregnant or not as that's a myth.