Hi! Thank you for the kind words!
To answer your question regarding open-source assets: Yes, this pack will work fine with your project!
If you include a brief ATTRIBUTION or LICENSE file stating that the paid assets remain under commercial license and are not covered by your code's open-source license, then you don't need to maintain dummy assets.
As you mentioned, compiled assets in game builds can always be extracted anyway, so having the asset files in a public repository is standard practice for open-source indies, as long as the asset license is there.
Really looking forward to sharing the Dev and Master tiers after the final refinements! Until then, feel free to share a link to your repo whenever you're ready. I'd love to see your work!