Having mini projects is a good idea. You can experiment with kinks and mechanics more boldly with them and take what works well into your main games. As a side effect, they'll keep the patreon funded and make the wait between main releases more bearable, so big thumbs up for that one! 👍
The rework Is a necessity for Grove to keep up with Prowler, but I'd caution against overdoing it, where every few years the game needs to be "remade". Happens to a lot of projects, and eventually the devs will abandon it because of burnout and boredom. Speaking as a dev myself, what I would do to avoid burnout is instead of doing a 1 to 1 remake, I'd do a re-imagining where new content is added to old areas alongside the boring work of migrating to a new engine. The content should take advantage of the new engine and features. This keeps development from getting boring (at least imo) and as an added bonus, you'll get something more exciting to show for after the engine change instead of the same old content after months of wait.
As for the double height sprite, I find it uncanny thb 😅 (at least in this rendition). I think the always visible full size artwork on the side like Prowler already has, does a better job of showing statuses, effects, and equipment.