Oncidium seedlings in S/H tips or suggestions?

[arianeos]

I have various oncidium seedlings in 2-3" pots arriving sometime next week as part of my holiday gifts from family. Normally I prefer adding larger plants to my collection, but my sister found miltassia shelob tolkien (we're LOTR fans) at seedling size along with a few others on my wish list. My adult oncidiums are all in 6" glass vases S/H culture, and the smallest other sizes I have are 5" for my phals. Nothing smaller.

Does anyone have experience growing tiny seedlings in much larger pots in S/H, or should I try to get something smaller for them? If so, any size suggestions or tips for seedlings in general? I want them to have the best chance possible. Thanks!