Having a ICAO non-Jar/EASA IR doesn't pass the EASA IR test for you, it just stops the clock from ticking from having to do a full EASA IR initial test or losing your ATPL subjects, so yes you would still have to pass a EASA IR renewal.
I think in your case, the 3-5hrs flying in type would also be covered in the 3-5hrs IR training they are asking you to do. I would argue about the 'in addition', does it say that in the regs? As for how much of that flight time you actually do depends on you. Aren't the rules a 'recommendation' of 3hrs not compulsory??
If you know the requirements for a EASA test, you are fully up to speed as you say on type and IR fly regularly then push for a Checkflight straight off, as this should satisfy "time required before test" and then do the test.
Make sure you have the regs to quote to the ATO, and if necessary an agreement from CAA in an email or letter to save you $$.
Are you doing all this because of lapsed rating and IR on the JAR licence, or you have a job offer? If it is just because of the lapsed ratings, then as long as you are remaining on type and IR flying on the other licence I wouldn't worry about it.