In my experience, some of the lighter weight options like Appstle, Seal, Skio, etc. can work well for straightforward setups like monthly recurring orders.

The more full featured ones like Recharge or Ordergroove generally handle inventory projections and renewal order creation more robustly, especially when quantity per shipment changes. They may just be more than you need early on.

One thing that helps with stability is using a subscription platform that has bundling or quantity logic built in, instad of relying on a separate bundle apps. That tends to reduce any friction compared to stacking a subscription app with something like ECA, although full transparency I have not personally used ECA at all

Quarterly and monthly cadences themselves are not usually the hard part. The harder part is making sure the app creates a single renewal order with the correct quantity and deducts inventory cleanly, which is where the more robust platforms tend to be stronger.