Is PCB tinning necessary?

[bool]

a). you should become more pedantic at the PCB edges/borders.

b). you'll get the hang of it eventually.

c). alternatively, you could look up for a small solder-bath ... eventually.

d). another DIY "don't try this at home" idea would be to use/apply the smt solder-paste and flux to your super-cleaned (!) bare PCB(s), then put this into your hot-air owen (if you have one). Usually works, but not always.

[karbomusic]

I am not sure if smelling burning laquer is a better option than torturous tinning.

It is better IMHO, I don't remember smelling burning lacquer, it's so thin.