MicrosoftSergei
<I only hope one day lambda will go out from name manager umbrella>
I see where you are coming from but I would put it the other way round. Name Manager never has been fit for purpose as an environment for developing Names. It is just sufficient if one restricts the idea of Names to be Named Ranges but once one tries to use it for developing formulas (range references being merely a special case) then the inadequacies show. A someone that banned the use of direct cell referencing within my spreadsheet formula some 6 years ago, I find I frequently need to develop the formulae on the worksheet and, only when they are validated, do I upload to the Name (on occasion using VBA utility macros) to allow the formula to be deployed.
Both LET and LAMBDA support the view of Excel as a programming platform rather than an interactive WYSIWYG environment for the direct manipulation of numbers. A major upgrade to Name Manager and Evaluate Formula is needed to support LAMBDA and any change can only be of benefit to regular Names.
Assuming one recognises LET and LAMBDA as programming, some additional syntax is needed to address the problems noted both here and in the comments above. An alternating pattern and comma-separated parameters is not sufficient. Some commas represent assignment of a formula to a name whilst others separate statements. In addition, the need for a third separator type as an escape to introduce comments (metadata) has been noted.
Possibilities might include
Assignment: , (current default) := (two characters but semantically intuitive)
New statement: , (current default) ; (as new row of array constant) ¶ (Pilcrow symbol displayed in place of character 10, linefeed)
Comment: (no default), \ (backslash, currently part of a legal name but used infrequently), | (pipe, available but may be a notational clash)
A further thought on Formula Evaluation. Wouldn't it be nice it the window were resizable (I would often use full screen) and one could use F9 to step through a LAMBDA or LET, evaluating the formula line by line?
