Hi! Cosmology/core is becoming deprecated soon, as the asset list is "baked in" and the code is legacy.
An ideal workflow is to use osmojs and @osmonauts/math, which we have examples as shown here and in a video/tweet here
then you can use the chain-registry for loading assets, and you can use @chain-registry/osmosis for pre-baked assets, or @chain-registry/utils to build an asset list dynamically:
import { ibc, assets } from 'chain-registry';
import { getAssetLists } from '@chain-registry/utils';
const list = getAssetLists('osmosis', ibc, assets);