Posible to implement for Fasmw line number Jmp?
For example

We get code without labels!
Some time its helpful.

Easy to implement. It is just some code to write to make a fasm version of your own that you like.

One method might be to have the preprocessor construct automatic labels and insert them before each line. Or maybe some other method if there is a better way to do it.

And if you post your changes here, maybe others will like it also and use it. Doesn't hurt to try.

what if line(from where jump happened) would be defined in macro? Where should go jump then? to line in that macro, to line in file where macro defined, to line in file where macro used?
It will bring in syntax more complexes.

Its good for smal peaces code.
Like as procs.
And Used only in non-macro.

proc is a typical macro for exampe.

But if thou mean this feature needed only inside of procs - thou could extend macro proc (but in fasmg) so each line of proc would be autolabeled.
Maybe when thou will see how compilation will be slowed after that thou will agree that convinience of autolabeling cost too much.

Line number seems arbitrary unless it's relative and even then it's not anchored to any text - so, would need frequent edits - the opposite of what one wants to achieve, imho.

Betov (of SpAsm/RosAsm* fame) liked a method which actually worked well in practice - cut-n-paste of code rarely required editing: it consisted of using <> characters to select the label - one < would mean the previous label, and two < would mean the label before the previous label.

[*] 32-bit assembler still active, very different from standard x86 syntax.

https://www.youtube.com/watch?v=qUCfFB4veY4&ab_channel=Roman8139