I guess it depends what answer you seek, and there may not be a simple or universal answer.
The limit for the lfm is afaik set by:
- What can the IDE handle: high(integer)?, memory available (e.g. 32 bit IDE, single biggest avail chunk of mem)
- How slow can the designer go before you get bothered
- What can the resource compiler take (to compile to the binary resource), probably high(integer) again.
...
Then what can be put into an executable: elf, PE, ... maximum resource size (single resource/all resources)
And in reverse the code loading your form, what can it take => probably high(integer). And how much time can it spent to load your form. And does it get enough memory.
If the size matters, because you want to fill your form with huge amount of TWinControls (rather than embedding a 8k image list into your form lfm) then you may hit limits with the OS/WS.
But that wouldn't be a limit of the lfm. If you have a form, and you have code that creates 10000 TButtons => that may be an issue for most/any OS???
For all else, it seems there aren't any intentional limits, such as the IDE checking for some limit set in the IDE. The limits, if any are inherited from hardware and other tools. And where/if they have there limits... Well that seems to be less well known. (And in parts is not about the lfm itself)