My guess is that almost everybody says 'jono' in 'krajono', but many will say kraj-jono rather than kra-jono. (Compare 'kaj Johano' with 'tra jaroj' )

This is of no consequence since, as far as I am aware there are no words in Esperanto that can be changed into other words by doubling the 'j'.

Generally, transforming one word into another by doubling a consonant is rare in Esperanto but there are examples eg fino and Finno.

Also in noisy environments careful pronunciation of a doubled consonant may help to distinguish one word from another even when there is more than a one letter difference - for example, ellasi kaj elasti.

However, it is very difficult to imagine how pronouncing krajono as kraj-jono can cause any problems - in fact, may make the word easier to hear as krajono than the pronunciation kra-jono.

Why not request sample pronunciations from different mother tongue speakers at Forvo