FMC holding leg distance

[Cheju]

Hi everyone, I'm just wondering if anyone can help me out for this.
I'm looking at the RKSI ILS 33chart, missed approach holding pattern,
It has got inbound fix "Ronji" D10 NCN as well as D15 NCN for the outbound limit. I understand this 5nm difference is slant range not linear. With regard to setting up the FMC for this kind of hold, Can I still put 5mile leg distance believing that we will still be protected(as differences are so little?) or just put 1minand monitor 15DME restriction?

Perhaps a similar example can be seen at EGKK ILS 26L, where the fix is VOR itself and outbound leg is 5dme..(I was told not to put 5mile but use 1 min..couldn't understand why.)

Would be appreciated sharing your opinion.
Thank you.

[ajd1]

I've never done the maths of the slant DME distance versus the actual leg distance, but we always put the distance in the Hold page and it seems to work ok. I suspect the difference is extremely small.

[Check Airman]

Just looked at the RKSI ILS 33L. I wouldn't over-think it. First of all, isn't the MAP already part of the database? If so, doesn't it specify a distance?

Secondly, you'll be holding at 4000-5000ft as indicated in the procedure. There's a reason for that. At that altitude, the DME error will be negligible.