I may stand corrected, but I think we have to clarify one thing: from the pic of the back of the vehicle, it really seems to be based on the Nona K, so it is not a howitzer, but a gun capable of firing mortar shells, and capable of direct and indirect fire support -here it acts like a howitzer or a mortar-.
It has completely different internal design and phisics behavior than howitzers, meaning it has a very low recoil force -like mortars- opposed to the "dental cavity filler" removal recoil effect on howitzers...
Technically, the Nona K achieved a recoil reduction of about 30% thanks to the characteristic recoil brake of this versión.
Again, I may stand corrected, but for me its hard to figure how this kind of vehicle could handle the recoil of a 120mm howitzer
Anyway, the design makes me guess how useful it may be against enemy vehicles, as the Nona K was... It seems quite uneasy to aim it for direct fire, so it would loose one of the advantages of the original towed gun: its great flexibility against different targets and tasks.