Visit visas at £78 a pop (for up to 6 months) cost less than 1/10 th of what you'd be required to shell out for a Civil Partnership settlement. But, of course, based on the exceedingly-low success rate for the *former ... there's no guarantee any further attempts at *it would fare any better.
Hence the reason why both Terpe and myself recommended the latter route. However ...... at the end of the day, only you and Steve can decide between yourselves.