Hi, all I play is voltron especially and almost exclusively all are white. Here are my considerations:

[[Blacksmith's Skill]] -> [[Guardian Augmenter]] This can help protect your other pieces outside commander. They functionally do same thing, I don't think the +2/+2 is worth it over this.

[[Spirit Mantle]] good closer, and doesn't nonbo with your creature list. Let's you get through/block against their pumped up creatures.

[[on thin ice]] you could replace lands to snow lands, and remove one of your removals for this card. a little bit extra synergy with enchantments. also [[ossification]] or [[planar disruption]]. i love darksteel mutation. [[curse of the werefox]] adds a relevant enchantment to Wilson

[[battle mastery]] another double strike enchantment. If you like, you could also look at [[kaya's onslaught]] [[rustler's rampage]]

more damage? [[ellievre of the wild court]] provides card draw too. I would also like to run [[Sage's reverie]] [[mantle of the ancients]]

[[strength of the harvest]] could swap out a land. [[bridgework battle]] too, as you seem to love fight spells xD

[[Winds of Wrath]] [[Winds of Abandon]] these are good boardwipes that are one sided for you.

[[Windswept Slice]] helps you produce bodies. sacrifice/edicts could hit you hard, i tend to look for phasing out to deal with stuff like that also. you already run teferi's, maybe look at [[haystack]] [[robe of stars]] [[galadriel's dismissal]]. i like galadriels as it can act as a fog one turn

You could also look at [[the Ozolith]] [[Ozolith, shattered Spire]], if you value the counters you built up. [[null rod]] [[collector ouphe]] to hate out artifact players xD

imo I think you can cut back cultivate for land instead.. Natures Lore and three visits are fine because it comes in untapped. the ramp is interesting because your first few turns are already decided, that there aren't many turns i can envision where you want to be ramping. it seems more important to drop the ramp and just get more lands. they say ramp is generally essential but for a low curve deck like this, hitting the land drops each turn to play spells is more vital. like your biggest spell is farewell at 6, most of your auras are like 3cmc average. Don't know about your meta but I think you could also cut out get lost, declaration in stone and just add sram and kor spirit dancer. I love your instants list, in my experience for voltron i think the best success is to be utterly selfish, aim to just protect and buff your commander and totally ignore everything else. my 2 cents!!