Yes, sufficient heat and air circulation.
I germinate tomatoes in Jiffy-7s with 95% success.
I have been giving away heirloom seedlings a month now.
If you do not have jiffy7s available , try supersoil potting mix .

Then, I let the seedlings grow a bit leggy. Snip off all leaves except the
last 4 or 5 top ones. Transplant horizontally with the tops turn straight up.
The 'limbs' ( for lack of a better word) will grow roots and give the plants
more nutrition.

Good luck.
HTH

/z.