I have 3 implements that have gear oil cavities. I have drained all three by hoisting off the ground , then tilting the unit to drain.
I have done this once for each unit, and I'm not doing it again. Ever.
I have a similar cultivator except mine has the tines attached via force fit wedges.
I pull it with my Steiner 420 with a cat 0 hitch.
I use a Aldo Biagioli cultivator with my Grillo 107d. It works great. I do have a small garden, maybe 1,000 sq feet.
Going too fast with a BCS/Grillo is not a factor, the manual shift models have three speed transmissions and the hydrostatic models have infinite speed adjustment.
If I had the Orec I'd get rid of the front wheels and put some skids on it. Front wheels tend to get in the way.
What you really need is a Steiner/Ventrac with a huge monthly pauyment.
I have a 30 year old Steiner that is a true beast.
I have a Grillo 107D with a 21" DelMorino brush mower. I've got hundreds of hours on it. Climbs hills, cuts brush, has steering brakes. I love it. If it can push it over, it can cut it.
One thing it doesn't do is mow in reverse, the pto disengages in reverse.
I've never run a flail mower.
I tried using a Brinley box blade behind my Grillo 107d. It did not work at all on tight gravel. It worked poorly on loose dirt.
Now, the Brinley was designed to be used with a CAT 0 hitch, so I did not expect great results. It does work okay when pulled by my Steiner 420 with CAT 0 hitch.
But...