I use neither the heat mats nor the lights. Admittedly, I sometimes experience some frustration because the use of either would help, at times.
Hired help might make things easier too but I don't have those extra digitS', either. Ideas for #1 paid labor, #2 mechanization with skilled hands running it, and #3 gardener in the lazy boy ... you will just have to put that under advisement, realizing that I don't have much experience except with #3 .
Seed germinates without any more light than what comes into my kitchen. I used to hurry emerging seedlings out to the South Window and under an 8' double fluorescent fixture. Ten years ago, we had remodeling done and DW is not receptive to the idea that we could put hooks back in the ceiling and suspend lights as we once did.
I once had those fixtures in the greenhouse, as well. One of them, anyway but don't see quite the same need as in the South Window of the house. The greenhouse has more sunlight.
Heat beneath the germinating seed would be especially useful for pepper seed and for any older seed. Slower germination is very obvious with both.
Since I spend a fair amount of time in the South Window during late winter (the pc is there

), I have been known to set the containers of soil mix with older pepper seeds on a hot water bottle with warm water in it. The room isn't very warm despite having that window.
Winter and Spring sunshine is too often in short supply for either warmth or heat here in what is
officially the Pacific Northwest. July comes and the area
officially becomes the Wild West with abundant sunshine!
Patience eases the gardening experience. I'm sure that this is true no matter where Mother Nature finds us.
Steve