The usage of "on the condition that"

I know that I can use the phrase ‘on the condition that’ with if clauses such as

• He agreed to work on Saturdays on condition that he was paid overtime.

But I’m not sure if I can use this structure like,

• I would recommend it to all ages on the condition that they’ve watched the other two films of the series.

I’ve used the word ‘would’ in the main clause but in the if clause I’ve used a present perfect tense. Would that be a correct usage? I also wonder whether I should use ‘on the condition that’ or ‘on condition that. I’d be grateful if you could answer those questions above.