In my opinion, it would be better if, for example, active subscribers had an automatic compacting function after 7 days, which stores the ship in a storage facility at the spaceport/market and then rent or a deposit is due.
And for this automatic compacting function on the market, the actual limits (container, mass, number of engines, etc.) do not apply, which are otherwise only so that you don't take the fattest parts with you in your pocket.
And the ship can only respawn at this market where it is storaged!
If the subscription expires while the ship is in storage, it could e.g. also be auctioned after a short time later.