Extrude one layer of blocks from another:
x = 1183, y = 49, rule = B3/S23
1036bobo$1036b2o$731bo305bo$732b2o$288b2o441b2o31bobo$287b3o257bobo
214b2o$133bo153b3o179bobo75b2o216bo$35bobo95bobo50bo100b2obo181bo69bo
5bo$35b2o96b2o50bo102b3o71bo109bo7bobo60b2o$36bo94bo53b3o101bo71bo107b
o2bo7b2o60b2o$34bo90bo3bobo29bobo27bo169b3o106b3o8bo55bo15bo$35bo90bo
3b2o29b2o19bobo6bobo344bo5bo6b2o429bo179bo$33b3o9bobo76b3o35bo20b2o6b
2o166bo112bo63b3o4bo8b2o427bo35bo3bo37bo56bobo36bo6bobo$45b2o85bo50bo
108bo65bo114bo2bobo64b3o38bo3bo392b3o32bobo2bobo36bo56b2o3bo30bobo6b2o
$46bo83b2o4bo26b2o126bo38bo27b3o61b3o46b3o3b2o103bobo3bobo366bobo56bob
o2b2o35b3o32bo23bo2b2o32b2o$36bobo92b2o3bobo23b2o23b2o102b3o31bo3bo89b
o2bo54bo105b2o3b2o367b2o25b3o30bo75bobo25b2o34bo$36b2o98b2o26bo23bo25b
2o36b2o30b2o40b2ob3o28bo32b2o25bo2bo129bo404bo25bo41bo34bobo29b2o62bob
o$9bo27bo121b2o26bo27bo4bobo30bo31bo39b2o32b2o26bobo3bobo22b3o131b2o
30b3o29bo210bo157bo35bo4bobo32b2o26bo25bo37b2o2b2o$9bobo56b2o30b2o25b
2o31bo25bo27bo5b2o30bo8bobo20bo74bobo26b2o3bo84b2o21b2o41b2o6bobo29bo
31bobo207bo132b2o59bo5b2o28bo5bo25bo25bobo35bobo$2ob2o4b2o15b2ob2o33b
2obobo26b2obobo21b2obobo26b2obo23b2obo24b2obo7bo7bo18b2obo9b2o17b2obo
30b2obo14b2o13b2obo26b2obo7bo20b2obo23b2obo4b2o23b2obo4bobo16b2obo2bo
36b2obo2bo2b2o22b2ob2ob2o5bo19b2ob2ob2o3b2o16b2ob2ob2o22b2ob2ob2o5bobo
16b2ob2ob2o31b2ob2ob2o37b2ob2ob2o26b2ob2ob2o4b3o23b2ob2ob2o21b2ob2ob2o
23b2ob2ob2o20b2ob2ob2o11bobo12b2ob2ob2o28b2ob2ob2o2b3o26b2ob2obobo18b
2ob2ob2o4b3o16b2ob2obobo29b2ob2obobo21b2ob2ob2o$2ob2o21b2ob2o33b2ob2o
27b2ob2o22b2ob2o5b2o20b2ob2o22b2ob2o23b2ob2o13bo19b2ob2o9bo17b2ob2o29b
2ob3o11b2o14b2ob3o24b2ob3o26b2ob3o3bo17b2ob3o2bo7bo16b2ob3o2bo18b2ob2o
bob2o33b2ob2obobobo22b2ob2obobo24b2ob2obobo20b2ob2obo23b2ob2obo6b2o17b
2ob2obo32b2ob2obo38b2ob2obo27b2ob2obo31b2ob2obo22b2ob2obo24b2ob2obo21b
2ob2obo12bo14b2ob2obo29b2ob2obo32b2ob2obobo18b2ob2obo24b2ob2obo31b2ob
2obo23b2ob2ob2o$9bo24b2o97bobo57bo34b3o23b2o4bo25b2o32bo12bo19bo29bob
2o28bobobo22bobo6bo23bobo24bobo8bo4b2o25bobo7b2o21bobo30bobo4b3o19bo2b
o26bo2bo4bo23bo38bo44bo2b2o29bo2b2o33bo28bo5bobo22bo27bo33bo8b2o25bo6b
3o29bob2o23bo30bo37bo4bobo$2ob2o3b2o16b2ob2o2bo2bo27b2ob2o27b2ob2o22b
2ob2o5bo21b2ob2o22b2ob2o6bobo14b2ob2o9b3o21b2ob2obo4b2o5bo13b2ob2obobo
5bobo17b2ob2obo26b2ob2obo2b2o19b2ob2obobo23b2ob2obob2o17b2ob2obob2o5b
3o15b2ob2obobobo16b2ob2obobobo5bo4b2o20b2ob2obob2o5b2o16b2ob2obob2o23b
2ob2obobobo2bo15b2ob2obobobo19b2ob2obobobo21b2ob2obob2o29b2ob2obob2o
35b2ob2obobo2bo22b2ob2obobobo27b2ob2obob2o8bo10b2ob2obob2o2b2o2b3o12b
2ob2obob2o18b2ob2obob2o7bo16b2ob2obob2obo3bobo18b2ob2obob2o3bo25b2ob2o
bo20b2ob2ob2o5b3o15b2ob2ob2o8bo21b2ob2ob2o3b2o17b2ob2ob2o$2ob2o3bobo
15b2ob2o2bo2bo27b2ob2o5bo21b2ob2o22b2ob2o27b2ob2o22b2ob2o6b2o15b2ob2o
9bo6b2o15b2ob2obo4bobo3b2o13b2ob2obobo5b2o18b2ob2obob2o23b2ob2obobobo
19b2ob2obobo23b2ob2obo20b2ob2obo26b2ob2obo2b2o16b2ob2obo2b2o5b3o4bo19b
2ob2obo10bo15b2ob2obo26b2ob2obo2b2o3bo14b2ob2obo2b2o19b2ob2obobobo2b2o
17b2ob2obobo30b2ob2obobobo34b2ob2obobob2o22b2ob2obobo29b2ob2obobo8bo
11b2ob2obob2o3bo2bo14b2ob2obobobo17b2ob2obobobo5b2o16b2ob2obobob2o3bo
20b2ob2obob2o4bo24b2ob2obo20b2ob2o8bo17b2ob2o11bobo19b2ob2o3bo3bo17b2o
b2ob2o$34b2o38bobo113b2o25b2o6bo5bobo20b2o9bobo18b2o7bo24b2obo29b2o28b
2o30bo26bo32bo26bo42bo32bo32bo28bo29bob2o2b2o24bobobo4bo29bobobo4b2o2b
2o30bobo31bobo3b3o29bobo8b3o15bo10bo19bo2bo24bo2bo6bobo21bobo33bo38b2o
25b2o6bo22b2o4b2o2b2o26b2o$2ob2o21b2ob2o33b2ob2o5b2o20b2ob2o22b2ob2o
27b2ob2o22b2ob2o3bobo17b2ob2o2b2o12bo16b2ob2o27b2ob2o29b2ob2o28b2ob2o
25b2ob2o27b2ob3o21b2ob3o10b3o4bo9b2ob3o21b2ob3o37b2ob3o27b2ob3o27b2ob
3o23b2ob3o24b2ob3o8bo17b2ob3o3b2o4bobo21b2ob3o3bo6b2obobo23b2ob3o2bo6b
2o17b2ob2obob2o2bo25b2ob2obob2o19b2ob2obo5b2o17b2ob2obo21b2ob2obo27b2o
b2obobo27b2ob2obo32b2ob2obo20b2ob2obo24b2ob2obo4b2o6b2o17b2ob2obo23b2o
b2ob2o$2ob2o21b2ob2o33b2obobo26b2obo23b2obo28b2obo23b2obo4bo19b2obo34b
2obo28b2obo13bo16b2obo29b2obo26b2obo28b2obo23b2obo12bo5b2o9b2obo23b2ob
o13b3o23b2obo29b2obo29b2obo25b2obo26b2obo28b2obo11b2o22b2obo11bo3bo25b
2obo4bobo4bobo16b2obo2bo6bo24b2obo2bo22b2ob2ob2o3b2o18b2ob2ob2o4bobo
13b2ob2ob2o2bo23b2ob2ob2o28b2ob2obobo30b2ob2obobo18b2ob2obobo22b2ob2ob
obo4bo5bobo16b2ob2obobo2bobo16b2ob2ob2o$68b2o31bo25bo31bo26bo27bo37bo
31bo12bobo18bo32bo29bo4b2o65bo4bobo52bo132bobo140b2o4bo23b2o36b2o6b3o
26bo29b2o24b3o64b2o37b2o25b2o29b2o10bo25b2o2b2o$37bo62b2o26bo31bo26bo
27bo7b3o27bo31bo11b2o20bo32bo29bo2b2o127bo131b2o60b3o116b3o35bo59bo27b
o33b2o168bo2b2o$36b2o39b2o26bo23bo31bo26bo25b2o7bo28b2o30b2o32b2o9b2o
20b2o11b2o15b2o4bo253b3o3bo60bo117bo2bo36bo85b2o29bo2b2o172bobo$36bobo
33b2o3bobo23b2o23b2o30b2o25b2o35bo71bo32bobo31b2o278bo65bo78bo40bo96b
3o54b2o3bo171bo$71b2o4bo26b2o189b2o32bo35bo19b3o254bo4b2o133b3o3b2o35b
o3bo96bo32bo22bobo$73bo109bo111bobo87bo2bo257bobo135bo2bobo39bo26b3o
68bo30b2o$33b3o29b3o35bo79b2o6b2o28bo163bo262bo134bo42bobo20b3o4bo89b
2o10bobo$35bo31bo3b2o29b2o78bobo6bobo26b3o8bo153bo3bo461bo5bo87bobo$
34bo31bo3bobo29bobo86bo28bob2o6b2o153bo395b3o8bo57bo96bo$36bo35bo112b
3o33b3o6bobo153bobo391bo2bo7b2o62b2o98b3o$35b2o37b2o109bo35b2o560bo7bo
bo62b2o97bo$35bobo36bobo109bo596bo71bo5bo94bo$74bo705bobo77b2o$860bobo
3$760b2o$760bobo$760bo$725b2o$726b2o$725bo!
I haven't yet developed the general case of putting blocks onto a surface, but it would likely be based off of this moving wick:
x = 2, y = 10, rule = B3/S23:T0,10
o$2o$o$2o$o$2o$o$2o$o$2o!
The only thing that I've seen generate anything close to it (so far) is this soup:
x = 17, y = 10, rule = B3/S23:T0,10
o2b2obo2b2obob2o$2o7b2ob5o$9bo2bob3o$obo2bobobo3bo$o3bo2bo2b7o$3ob3o3b
2o2b2o$3b4o3bo2bo2bo$bob2obob2o2b2o$o4b2o3b3o2bo$5bobobob2obobo!
(I find that T0,10 offers a good balance between everything going linear and requiring a large number of tries for it to go linear just once.)