What's your "Mac Tower"? Specifically the CPU and RAM. Those things could have upwards of 12 cores and 24 hardware threads and have as much as like 48GB of memory. Doesn't matter how much faster per-thread the MBP might be, the extra cores/threads could make a huge difference. Also is your 2016 MBP a 13" model or a 15" model? The 13" models all have dual-core CPUs, so you may have a pretty weak CPU as far as these things might go.
PT11 doesn't have freeze tracks, so you might need to manually print some of those plugin-intensive tracks to another audio track with the effects in tow. That'll let you disable the plugins on the original track. Then you can mute it and save some CPU if you know that track is done.
Freeze tracks made it into PT12. But PT12 is a ridiculous yearly subscription or $800 for a perpetual license that you get to re-pay for PT13. I got off the PT bandwagon and bought Logic Pro. $200 and no subscription. It's the best music production money I've ever spent. But if you're used to Pro Tools then you want to get it to work right, so that's why I talked about printing your tracks before ranting.
I do not understand what I do. For what I want to do I do not do, but what I hate I do.