For me the upsides of the Schmitz32 seem to be the horizontal (depth, in relation to the front of the workpiece) rails with index notches for the vertical rail, the numbering for the holes, the registration which -as long as you stay in one direction- dosn't need you to press some button, the single point clamping and the ability to easily lift the vertical rail away from the workpiece.
Downsides seems to be that the workpiece needs to be smaller than the vertical rail for the horizontal ones to be useable at all and the need to have it installed onto a surface to keep it aligned (I don't see me carrying the system to a jobsite as me being more of a 'hobbyist' lacking a large van to move it in an assembled state).
The LR32 has the upside of being mobile with the bulkiest part of it (the rail) most likely being at hand anyway (for use with a TS).
Downsides are the horizontal (relative to workpiece) depth arms (SA-LR 32, which are strange compared to nearly all other festool stuff: overly thick and heavy) which are short so you can't reference everything from one edge for deep workpieces, the hazzle to change depts on them (no index notches to catch at default depths) and the need to always clamp the rail after positioning (to make sure it won't move while boring the holes).
As the SA-LR are relatively cheap (at least for festool standards -70€ incl. VAT for two-) and once they're setup they seem to hold their setting (as long as you only detach them on the rail side) one could get an additional pair to use for registering from the back of the workpiece (requires to rotate the FS which is cumbersome) -or- the back of the workpiece and
the FS (instead of toward the splinter guard side, giving the SA-LR more reach as the ridge they connect to is near the back of the FS - way harder to setup correctly though as you can't use the notch in the LR32 baseplate to zero the SA-LR scale in this configuration). But more columns of holes are not really fun to make, as you either need more of the SA-LR, need to reset them repeatedly (with the likeliness of introducing errors) or need to use them to index from the last column of holes created (with the possibility to introduce cumulative errors).
So as long as you only need two colummns of holes (you would need to be ok with boring additional holes between the two columns created with the LR32 for heavy duty drawer with a self-centering drill with the drawer rails already installed - another can of worms as this might contaminate the drawer rail with shavings) simply getting more of them could be a way to go. But the need to rotate the FS 180° and/or register with the SA-LR out to the back of the FS is cumbersome and still might fall short on deep cabinets.
The missing hole numbering could be added using a sharpie and I think I can live with having to actuate the release button on the sled.
Bottom line: the limitation of the Schmitz regarding workpiece size is a real downside, as is the limitation (for me) to stationary use - for the LR32 it's the hazzle with depth positioning and repeated clamping (and the positioning of the clamps as they need to be removed to lift the rail from the workpiece).
The best plan - at least for me as I already have the LR32 - would be to retrofit the quick and easy depth registration from the Schmitz32 to the LR32 (using a small and somewhat simple jig, ideally without the limitation on workpiece length should one not have a long enough holey rail)... I have some ideas how to pull that off but want to test them in practice first (no need to send others onto a snark hunt
) - might take a while...