This x 100
If this programs feels “too easy” or if you feel like adding more volume it’s because you aren’t doing the work sets hard enough.
As for doing abs, people here know my stance: I train abs in blitzes: for 3-6 weeks I train them every day… normally I do a superset of 2 exercises, one loaded, one unloaded and do the superset 3x. This is done at the end of every workout. Then I stop training them directly for 2-4 weeks and abs are likely my best body part.
Calves I honestly never trained them in my life and I have decent calves. I find that calves is something that you either have or you don’t. Those who are blessed with great (or good) calves (due to long muscle bellies) don’t need to train them directly and those with REALLY poor calves (very short muscle bellies, long tendons) will not be able to significantly change them even with specialized training. The only people who can benefit from direct calves work are those with decent calves but who want more: they have a muscle belly long enough to create a visual size gain but not enough size yet to not need it.
I guess you can add one exercise of calves twice per week and it wont affect recovery.
Traps are normally hit with any pulling action. I’d wait to see how the program works before thinking about adding traps work.
And you can’t simply ADD ON volume. Normally when you add something you must take out someone of an equal stress level