Departing Laos - will any crossing do?

I entered Laos on an eVisa 44 days ago. Are there any restrictions on which border crossings I can use to depart Laos when my stay expires? Does anyone here have experience with departing Laos at one of the more remote border crossings? Reports of sizable bribes being demanded by Lao officials at some checkpoints are worrying. Lack of regular public transit is another concern. Hitching a ride may be the only way to get from Khop district in Xayaboury to Roumsuk in Thailand's Phayao province. The Pang Mon International Checkpoint has two angry Google reviews from recent months detailing experiences with corrupt Lao officials. Backtracking to Ngeun district seems to be preferable.

There appears to be regular van and songthaew service across the Nam Ngeun crossing, which is the principal port of entry for northern Xayaboury province. Nan province on the Thai side looks beautiful and worth visiting as well.