I would first obtain an order from the MD for a wound culture and an ABI. The hypergranulation suggests to me that it may be infected or may be too wet. My go to dressing in the meantime would be a silver alginate and foam to cover, kerlix and two layers of Tubigrip.
If the culture is positive, hopefully MD will order an abx. (The hypergranulation might need treated with silver nitrate stick, but this may need to be done by MD or perhaps a certified wound care nurse - depending upon agency policy. Sometimes, the silver alginate and foam will knock it down though.) If the patient's ABI is 0.8 to 1.0, then it would be ok to compress and I too would go to the unna boot - same cover dressing: silver alginate and foam till abx completed and then maybe just a foam with Unna Boot to cover. Should be able to leave in place for 5 - 7 days.