I don’t love Stern Avatar either, but there is more to the game than just stacking Link and Amp.
For better scoring, there is a system of shot multipliers, completing the top lanes lights all major shots with a white X. Next white X shot made puts a 2x multiplier on that shot for the rest of the ball. You can repeat this over and over so if you push the risk you can potentially have 2x on all major shots, and then you can also get a roving 3x on one shot. The risk is that the feed from the top lanes goes through the pops and depending on the machine, this feed might not be nice.
Even playing Link MB by itself, once you collect 15 jackpots there is a 3m super and a 6m double super on the Link shot, so if you have 2x on the Link shot that’s 18m alone.
You can stack more modes into Link like Navi scoring, Seeds and especially bomber battle (especially if you’ve been shooting orbits for the top lanes to get 2x multipliers), then when in Link you can progress towards Amp with lower risk. Get the Link add a ball early (locking a ball back in Link and hitting it). The captive ball mystery can also give you an add a ball though from memory it’s not always the first award and if you took other modes into Link MB then it might add more time to those modes instead.
Shooting Amp in single ball play is one of the ways I often get myself killed, especially once the magnet wakes up, which is why I’ve started shying away from trying to get it ready in single ball and only start hitting it in Link MB instead. Others may do this differently.
Peter is probably about to come back with an even better strategy, but this is how I’ve recently started trying to play the game as a not great player having previously just done what you did. Get the 2x on Link at least or more if feeling good about the pop feed, get Link going, add a ball, focus on getting jackpots and work on Amp, then maybe the stack does come in but it’s more profitable. Actually doing it is the hard part