What's the highest possible Sign intensity?

First of all I like to point out that I want to get the highest value without any conditions for it to trigger, so no "Focus" ability because it depends on adrenaline points. Also no temporary boosts like potions and decoctions.

Personally I believe it is achieved with following stuff:

• All legendary (NG+) mastercrafted griffin items. Unfortunately I don't know the stats for them yet. regular mastercrafted would be 70%
• Sword sockets full with Greater Veles Runestones = 15%
• Armor sockets full with all Greater (any) Glyphs. 3 in chest, 2 in legs, 1 in boots, 1 in gloves. Is 7 times 10 % divided by 5 (because single element) = 14%
• "Griffin School Techniques" ability = 20%
• "Synergy" ability (see mutagens)
• The 5 blue abilities that grant 15% for each element respectively = 15%
• Fill the other abilities with other blue abilites
• 4 greater blue mutagens. Each normally gives 10% but because of "Synergy" 15% and also 15% for each blue ability. because of the 2 nonblue abilites we have = 60 + 60 + 60 + 30 = 210%

So now we have 344% sign intensity without legendary stats of griffin and from leveling up.

According to https://www.reddit.com/r/witcher/comments/373bus/sign_intensity_explained/ you can get 28.1% from leveling up. Don't know if this still is acurate with the latest patch and NG+ but this would lead us to 372.1% plus some from the legendary items.

Is my setup optimal? and if someone has the stats from legendary mastercrafted griffin that would be great, I can't find it online.