I've not done any training at Oxford, so I don't know what their attitude towards this would be. But I would expect any decent school to be flexible enough to allow you to do as much training as you want on more complex types, as long as you were prepared to pay for it, and as long as they didn't feel you were trying to "jump in at the deep end" as it were. So speak with the CFI, and see if you can do more time on the PA34 and less on the PA28 if you're concerned.
FFF
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