Spreadsheet for BMR/TDEE Deficit calc, Macro calc, HRM

Ok, so you have a tad less LBM than avg for person your age/height/weight.
But that's good to know, and great reason you don't want to eat too little and possible lose more. You need it all.

So you need to figure out which is more motivating to you.
I scheduled 5 hrs of weekly exercise into my daily avg eating amount.
or
I want to eat some extra each day and that motivates me to work out.

If the former, use the BMR/TDEE tab and be realistic for the amount of hours you can get yourself to workout weekly.
Take which ever deficit method is appropriate.

If the latter, use the MFP Tweak tab and use the RMR as lower value to hit each day, and since using a HRM eat back extra when you burn extra. Don't worry about getting it eaten within that day before midnight, but before the next workout at least in 24 hrs. So in the green one day, in the red the next.

I noticed I can eat more and do cardio with the way the formula calculated, but I would have a smaller rate of loss that way (ave .54/week) compared to if I did heavy lifting I could lose at a higher rate on average but eat less (ave. 1 lb/loss per week)?

I'm a bit confused by this, too--the sheet directs me to eat about 250 calories less if I'm doing heavy lifting than if I'm doing mostly cardio or no exercise at all. Can that be right?

Sure, read the study, if you do weight lifting, you can retain your muscle and therefore take a bigger deficit.

If you do a little bit of lifting, you could also split the difference.