Have you tried the solid porridge fingers instead?
I never made them but they always seem to have a great following on BW and across parenting foodie sites etc.
Thing is with some LOs the thick mush sticks in the mouth and is harder to manipulate to push forward with their tongue so they might gag more, the lumpy food is a surprise and they are not sure how to deal with it so reject it or again gag as they are not manipulating the food in their mouth before it reaches the gag reflex.
Your LO is still very young and I don't see any harm in continuing puree a bit longer but it's recommended not to delay too much on the finger foods because of the various developments it helps and because some who stay on puree for a very long time then find it really hard to move on to proper meals.
Soft veg batons which pp suggested are firm enough for LO to pick up an manipulate in their hand and mouth so they have more control over it but also soft enough to squish into a mush in their mouth. Steamed carrot, parsnip, celeriac, turnip, sweet potato and fruits such as apple and pear either lightly steamed (not too long or they fall apart!) or oven baked (better as the outside is drier to pick up but the inside is soft almost like puree), all these things served in large batons or wedges might be more preferable to lumpy foods.
Have you tried little pancakes? It seems to be another fav amongst BLWers. My DS ate loads of them. Little fat ones like American or Scotch pancakes - self raising flour, egg, milk (or water if you are not doing milk) makes the basic batter but you can add apple puree or grated apple or carrot, whizzed bananas, all sorts really. They are easy to pick up and not lumpy.