Small Insert - Air Control (wide open?)

Hi, I doubt that you even saw secondaries yet. You gonna see secondaries when your stove is up to functional temperature and your pimary air is significantly reduced . You are asking if it's OK to burn small amount of wood in your stove and you are saying that you see secondaries with air wide open.. It's giving me a hint that you don't do it right.
Do this instead:
Load your stove well and build a nice hot fire . Bring your stove to working temp with open primary air. You can point your IR gun at the top of the insert inside your blower grills , Should be around 500f or so. If you dont have IR termometer just wait when all of your wood is on fire and burning hot. Then start to close the air . You will see lazy bluish beautiful secondaries, not the orange dancing fire you saw before. That how you do it. I think you are ubderfiring it.

Your wood might not be fully seasoned. Splits needs to be less than 20% moisture content as measured from a fresh split on the inside surface.

These stoves work better from full loads , try a top down fire starting technique. Which means fill up the stove with dry wood but leave enough room on top of the
wood splits to place a small amount of kindling and a fire starter like a Super Cedar. What this does for you is the full load of wood only leaves a small amount of open space up
at the top of the stove where the secondary air comes in. This small space with the small thin pieces of really dry kindling along with the Super Cedar , this space acts like
a small burn chamber and with the fast hot burning kindling and fire starter will heat up the stove really fast and the small space is easier to heat up than a very large space
of a mostly empty stove. You can crack the door to let a little more air in but dont leave it open to long as extra air flushes your heat up the flue. Its a seat of your pants feel
but get the door closed as soon as possible then only leave the input air fully open for a few minutes then reduce it by a 1/4 to 1/3 ways increments. After each new reduction of input air
wait a few minutes to let the fire stabilize at that new setting then once again reduce the input air another 1/4 to 1/3 ways. The stove is stabilizing with each new setting as these stoves
can burn at lower and lower settings as the heat builds in those insulated fire boxes. Thats why you got to get a feel for it as if your lower the air a little too soon and the heat hasnt
built to a higher level you could kill those secondary flames. The idea is to keep reducing the input air inn increments but not kill your secondary flames. Kindling and fire starters help all this
as they will burn hot and fast even with the door closed and at lower input air settings. Being able to have something like kindling and a firestarter burn with lesss air flow thru the stove means
less heat is flushed up the flue and the main objective here is to build the heat up inn the firebox so the secondary flames will burn at your lowest input air setting.

Once you have a good bed of coals to work from things are easier but I suggest to keep using kindling and a fire starter to get each new load of wood started as the faster you can get a new load of wood started
and the input air back down to your all day or all night burn setting then your gonna get more burn time out of your stove. I have had issues in the past of using not so dry wood and messing around
with the stove to get it going and what I noticed was when it takes longer to get the heat built up so I can get the stove shut back down to my all day setting or all night burn setting ,well what I did was
burned up alot of my main wood load and my stove did not have as long of burn time.

Dry wood and good kindling and a good fire starter makes all this really simple.

Watch this video
https://www.hearth.com/talk/threads/how-to-start-a-fire-video-top-down-method-and-other-tips.92574/

and look at this for the rake coals forward technique:
https://www.hearth.com/talk/threads/rake-coals-forward-and-stove-start-up-pictures.80659/

Lowes sells moisture meters.

I have a Jotul 350 insert and it is about 1.2 or 1.3 cubic ft. I also have a Jotul F500 wood stove. My first year with the 350 insert I tried to run it like my F500 always closing the air supply all the way down. I found that the 350 insert is a much better heater when I run it without the air closed all the way off. I just don't think you can get enough wood in these small stoves to really cause much of an over fire situation. I wouldn't be concerned running the 350 wide open for an extended period of time. Do that with the 500 and I think I would return to a pile of molten cast iron.

For your specific problem description I tend to agree with Huntidog1 that the wood might not be quite seasoned.

I have a small insert and I find with it 3/4 closed I get my best temps. Of course you need dry wood for this.