Of the non-PRC nations bordering the SCS (Vietnam, Philippines, Malaysia, Taiwan, etc), Vietnam probably has the best capability to do reclamation.
However, they pale in comparison to what the PRC is doing.
So while Vietnam can pick and choose a couple of islands to work on...and take some time at doing it, the PRC is doing massive reclamation on over a half doze islands at one time.
None of these individual nations have a hope of matching or keeping pace with the PRC.
They have to much more carefully pick and choose what they can do...and yes, Vietnam in particular is trying to do so. Philippines less so, IMHO.
I don't sure about when did PRC plan was began, but for Vietnam, it's simple thing that VNese must do since they took control from Republic of Vietnam in 1975.
As you all know, Spratly was most small Islands or sand field in vast sea, so VN started reclamation from long time ago, expand Islands, build harbour, to improve condition life of inhabitant (just like how did China do at Paracel, after they take it).
After DOC, all parties agreed that they will not take more reef, Islands, don't build new outpost, don't make new tension.
I will not saying PRC's reclamation and actions violate anything, but their plan and work made DOC become crap ... their work went beyond far from anything made by other parties, just like their claim in dash-lines map.
There's report said China bring material and equipments on
Eldad Reef (which under VNese control), many time, but everytime, VN sent men to prevent their plan, surely, VN don't want to has "
scarborough shoal" case before their nose.
It'll be damn tension if PRC declare new ADIZ on SCS.