If I'm thinking to move a miniature a certain way (but have not declared an order on it yet), can I check if the ways is large enough (half its base) for it to go and if the obstacle are low enough (lower than its silhouette) for it to glide ? I can't find anything in the rules that says yes
Typically no. You cant measure anything ahead of spending the order. But talk to your opponent. Its not a fun time spending 5 orders before you realize you cant vault that thing over there.
In N4 you would be allowed to spend an order, declare move and then check the gap before committing to a specific movement. Anything else I would pay to ask your opponent if they object before going around checking gaps for the full table.
