Hi, Clusterpod.
My day-to-day work preference runs to the SORD pack, but for those times when one can't avoid carrying >40kg, the DG8-SF truly comes into it's own. In any case, I hope you use yours at least occasionally; it'd be a rather expensive whim otherwise!
WRT your first question I've used some of my 'play' gear for work over the years, as my preferences run towards earth toned hues anyway. So I'll use, for example, One Planet sleeping bags inside a One Planet AUSTCAM bivie bag, or a 'Hennesy Hammock' if I'm on exercise somewhere Tully-esque. I'll habitually wear certain fleeces/2nd layer gear under a bespoke para smock when it's cold, and I'll always wear decent socks regardless of the boots I'm wearing on a given day. Finally, I'll use decent cooking/eating gear; or should I say I will unless the RAAF is ferrying me from Point 'A' to Point 'P'.
Issued equipment was pretty grim when I enlisted two-and-a-bit decades ago. Consequently, soldiers invariably pushed the envelope by using (then) cutting-edge bushwalking gear as and when they could. Over the years things have (slowly) gotten better, but much of what we use is still too heavy, and much too 'cooky-cutter templated'. Anyone can be uncomfortable in the field, and I really hate being uncomfortable needlessly.
Finally, and WRT your second question, when it comes to boots I suppose there's always been a measure of overlap between 'work' and 'play'. When in barracks it's Danner 'Arcadia' boots; in the field it's either Scarpa SLs or Merrell 'Moabs'. (Several years ago I had a Para Rigger friend make me some 'über-gucci' gaiters in AUSTCAM canvas and cordura, 'loosely' modelled on my S2S 'Quagmires'. These remain de rigueur items anytime I'm bush-bound with work).
All the best.