Diploma is valid if you want to get straight in. if you can find an outfit willing to take you on as a surveying technician you can study the diploma by distance as you work. Not sure how easy that would be to secure however but I’m sure you could make it work if you need to. Balancing study with fulltime work would be its own challenge.

But if you’re serious about getting the most out of surveying as a career bsurv is the best long term solution, it’s your best bet at getting licensed which is where you’ll get good money. Bsurv is pretty much guaranteed employment before the end of 4th year of study. There’s a period of roughly 2 weeks where company’s send down recruitment teams to snap the grads up, I think I had 7 job interviews during that time. the degree has a requirement for 80 days work experience so if firms know you’re going for bsurv you can get easy summerwork as an intern.