Would you call out this splice in this furnace cabinet? I am just nit picking?
Thanks!
I would say that the cabinet is designed to contain fire! 
What about the plastic connection at the top right side of the pic? That’s from the manuf. I would say that it is going to be OK. I have found the installation instructions in the same area as your splice. The book was made of paper. Stupid place to leave it after two years. installers left it there, home owner never knew it, buyer was glad I found it. The book was a little brown in color, probably a few months (if not days) of catching on fire.
That is the “hot surface ignition” component. It gets hotter than hot…
I always thought ground wires were way over rated.
Which model Lennox is this? There may be a bottom burner cover plate missing.
As far as the electrical the furnace does come with a small metal cover box that the white and black wire was connected to. The box can be moved from the left side to the right side.
If I saw this situation, I would call out the unconnected ground wire, but otherwise it looks ok to me. I would be less concerned about the splice than about the loose wires - but since that’s where the manufacturer put them…
That’s a Lennox. Lennox provides an electrical box that the original black and white wires, not the romex cable, were installed into. The box can be relocated to the right side. The installer(s) removed the cable clamp and box from the install and tossed it.
The other thing that I wanted to point out was depending upon model number that there may be a lower burner plate cover that may have been removed and tossed as well. Granted not all Lennox models have this lower burner plate cover but without a model number that cannot be determined. This would be clearly a modification that would derate UL certification.