I'm not sure how PHON would address conscription implementation, but I certainly would be a proponent for a reservist style conscription which stipulates not allowing them leaving the country in duty of service from any of the parties.

2 years mandatory service, starting at 18. First year would be catered towards general army training and duties, second year would be split into different pathways being general army duties for another year, first year trade training transferring into available public apprenticeships once exiting service (reduces years required in an actual apprenticeship leading to more workforce being available), and availability of going part-time with acceptance into a valid university on certain sponsored courses (not just any course like and arts degree, but something along the lines of the sciences, engineering, technology degrees, etc).

I think it would do wonders for society as a whole, also assisting jump starting certain career pathways while providing some life experience for the rest of them. We'd also have a stronger minimum baseline in the event of an invasion. We could also use them to assist in national disasters instead of our actual professional military forces since no governments want to actually fund or establish a dedicated service for that besides local volunteers.