I don't think the 20mm will be the secondary gun. This class of KCR even it's smaller sister KCR 40 have two 20mm gun on top the aft superstructure. Seems it's being used for self defense against small boats during constabulary duties or coastal operations.
For KCR 40 as it does not have position in aft for secondary guns, the 20mm can be consider secondary gun placement. The AK630 being used as Primary gun and CIWS for KCR 40.
While KCR 60 at least the Batch 1 put AK630 as secondary and CIWS. I'm still not finding clear information on what they are going to use as secondary and CIWS on Batch 2&3. Just looking with KCR60 batch 1 even smaller KCR40, seems the Navy wants to maintain function of CIWS.
That's why looking on secondary gun placement available on KCR60, I'm not convince they can put Bofors 40mm there. For that I suspect either Mistral Simbad RC or back to AK630. I don't think even Rheinmettal Millenium gun will be. It's bit bulkier just like Bofors 40mm for the available space.
Kapal Cepat Rudal (KCR) 60 Meter merupakan salah satu produk Alutsista yang merupakan state of the art PT PAL Indonesia (Persero) di mana keseluruhan proses […]
According to PAL they calculate 5 days for endurance with cruising speed of 20 knots. The operational range calculated by PAL is 2400NM. Thus if they're doing constant 20knots whole day, then seems it's in line with 5 days operation on operation range of 2400NM.
If not mistaken (can't find the article) there's local media that doing interview with TNI-AL spokesman. He said in average KCR type vessels doing operation for 10 days up to 2 weeks.