I guess you missed my comments about testing. Sigh ....
I did so apologies.
I would rather see fpcupdeluxe ship with a tested combination of products.
That is not the aim of/for FPCUpDeluxe. It is a tool that either downloads and installs optional a) a released compiler version b) a released lazarus version or c) fixes for one or both of them d) trunk (main as you name it) for either one of them and d) any cross-compiler .
Additional FPCUpDeluxe is able to bootstrap that for you and provide all the necessary (cross)tools and startup code for selected (cross)-targets.
At present, fpcupdeluxe, for Pico, points to main for both fpc and lazarus. Every time a merge happens in either, fpcupdeluxe gets a new, untested product to install. Given there is no benefit in tracking main in either, choosing know good snapshots would, IMHO make more sense. But its quite unreasonable to ask DonAlfredo to do that testing. I suggested, in the atypical case of Pico (and probably similar) he should request users of Pico to run some tests for him.
Yes, that comes with the territory. FPCUpDeluxe allows you to fill in hash codes for revisions in trunk (either FPC or Lazarus) so that we the users are capable of selecting the source from any commit that we want to use. Same as you can do so manually with git.
So that leave us the users to find a few hashes that work for us, in particular for the pico target if you wish.
There really is no point for Don Alfredo to do that for us (I get it that you want to offer your help with that) as there are literally dozens of targets to keep track off (that is practically work for ages).
So build FPC and Lazarus finding a hash that works for you and write it down somewhere for later use (wiki comes to mind). But do realize that whenever a stable release is able to target your preferred hardware there is hardly any point in upgrading unless the rtl for that target changed or was fixed (or in case you really want to use that new cool feature that was introduced in trunk).
As far as my knowledge goes that means stick to a stable Lazarus release and use (some version of) FPC trunk (and which version that is, is something that we can determine by its hash). And that is even if you want to rely on Lazarus (I myself do not use Lazarus for development). I personally have no time figuring out which version of Lazarus and FPC work together (or not), for me it is either it works or it doesn't and on occasion I let my build-script try and build a version of FPC trunk and Lazarus trunk (and in case it works I then determine whether or not I want to keep the produced archives).