Easy. I've done it. A decade in a pot-

Pindo palms are EXTREMELY slow growers, so they are great for bonsai. I grew one from seed in a 5 gallon pot for 6 years. Seriously, they are notoriously slow growing.

Recently picked one up. I just found out these are hardy to zone8!

0plantqueen, What climate are you in?

I disagree that they are "slow growing". Not in the least, if happy. I got mine, small, MAIL ORDER IN NJ a few years ago. I have three MASSIVE ones now. THEY ARE HUGE and in my LARGEST TUBS. They are outside from March till early December, then go into the garage. None of my other palms are as robust. My zone is 7A. If yours are slow, they may not have enough space, or maybe they just prefer life up north.

When grown from seed most palms take much longer to do anything.

Have not grown Pindo Palm from seed (but have grown Phoenix canariensis and Washingtonia filifera and robusta). Yes, most palms are slow from seed (Washingtonia are not that slow though). No cold dormancy and HEAT is important for germination. If your summer climate is hot, heat is obviously not necessary if planted somewhere outside but indoors, some bottom heat really makes the difference. Also, don't keep the mix too moist.

PS., I wonder about using the term "bonsai" though for containerized palms. In my opinion, neither palms nor cycads lend themselves to true bonsai cultivation and I have never seen one in professional bonsai collections. I don't think palm roots handle the routine root pruning so well.