Novus to Nexus. How do the secondary stats upgrade?

From what I understand, going from Novus to Nexus upgrades the stats according to the new i115 level. Easy enough for the main stats, but the secondaries that we add/change, how do they upgrade?

Many people have said that upgrading only two secondaries, which means spending millions of gil was the way to go for the maximum benefit. While others say that the difference from NOT using all materia IV was slight at best and it is fine going with a 3 stat split to save gil. However, with the nexus upgrade, I'm not so sure. This is why I am trying to confirm how the secondary stats increase with the new i115 level. Do they increase according to the proportion you put on the weapon, or do they upgrade according to what any i115 would become? Or do the secondaries not increase at all while only the two main stats increase to i115?

Either way I think about it, it seems if you really want to continue with this weapon and make sure it's as good as possible, you have to pucker up and just spend the gil and max out two stats. In my case det and crit (smn). I was planning on going with the det/crit/acc split but I'm not so sure now.

I thought only the main stats upgrade while the secondaries stay the same?

Nope the secondaries upgraded. But not a lot. My Novus had 44 crit and 31 det, after upgrading to Nexus it becomes 46 crit and 32 det.

That's about right for a 5 level increase. i120 would be 47 and 33. I think the OP is more interested in what happens with weapons that are carrying 3+ stats. I would assume that each stat would get a 1 point increase if there was 3 stats for the 5 level increase since there appears to only be 3 stat points to distribute. It's also possible that the first two stats would increase at +2 +1 rate and the third stat wouldn't change for the 5 level increase, in which case a ten level increase would be +3 +2 +1

Awwww man I was hoping for stats increase for all secondary stats. I put. PIE,DET,CRT and Spell speed. On my SCH book.