The simple explanation is as I understand it, there is no advantage to doing so right now. You have to look at exactly what Marlin 2 itself is all about, and how this applies to the current design of these (and other 8 bit boards in printers already on the market) In other words, its too early.

Will it help you get better prints? No .

Am I working internally with Marlin 2 here? Of course. But I wont release anything I wouldn't put into production on my own farm here.

Right now with the Marlin 1.1.9 Advanced, just about anything you could ask for is already present:

Features Enabled:

Save to EEPROM

Enabled EEPROM to persist settings. Now you can store PIDs and Z offsets to EEPROM. P.I.D. Autotune - Extruder AND Bed In One Operation

PID Tuning improves your hotend/bed temperature stability and will positively impact print quality. This command initiates a process of heating and cooling to determine the proper PID values for your hotend. This may take up to 10 minutes. During the tuning process the LED will stay Red. Once the process is finished, the LED will turn Green. Make sure you wait! Your machine specific PID values are now in use. However, if you want to persist your PID settings you must execute “Store to EEPROM”. Mesh Bed Leveling

Mesh Bed Leveling (MBL) allows interactively measuring a Z height mesh without a bed probe (like BLTouch or similar). The only tool required is a piece of paper or a feeler gauge. MBL uses the mesh to compensate for variations in height across the bed. You simply begin the probing and hit save at point 9.

Linear Advance

Linear Advance is now activated, but the set the K_Factor to 0, so it is disabled. To enable it using gcode you should first calibrate your specific K factor. You can do this Linear Advance is now activated, but the set the K_Factor to 0, so it is disabled. To enable it using gcode you should first calibrate your specific K factor. You can do this HERE . Accordingly set the K factor within your slicer or command interface using e.g. M900 K0.2 (as an example) Preheat Preset for PLA Its with the PID Autotune and MBL section to keep things tidy- it lets you easily preheat to given preset, you can change the temps in the mks_config.txt. Live Adjust Z / Babystepping Z

During printing the first layer you can still adjust the distance between the nozzle and the print-bed. E.g. if you find your print is not sticking you can carefully step down the nozzle or correct it up again without the need to re-level all four screws at the same time. However, this assumes the bed is in level overall but maybe just a little too low or too high overall. You need to execute Store To EEPROM to persist Z Values. (There is a Save to EEPROM in the interface for this) Having a mesh set with MBL can mess with this and visa-versa so understand that.

Easy To Flash

I've compiled it into a convenient HEX file so all you need do is load up your favorite slicer (that supports it) and flash away, no need to load Arduino and compile, upload, etc (the archive will contain the source if you really want to go that route too). Of course you still have to disable the TFT connection from the mainboard.

As for BLTouch or other auto leveling sensors...

First off, my opinion is that they are just another way to compensate for uneven beds, require hardware upgrading (and for some of you, out of the scope of your ability- its not a novice upgrade operation) and really cant solve anything MBL doesn't already. Why can I say that? A 20 minute firmware update vs. printer hardware modification, bracket printing or purchase, wiring, soldering, etc.

Easy.

These systems that compensate for your print bed being uneven dont solve the actual problem, only (using the word a second time for clarity) compensate for it. The underlying issue in extreme cases means a bed change, but most of the time its a solution to help out with the ever present variation almost all print beds do come with and they DO work for that.

So then, I ask myself, what else? The spring tension system can be the culprit- in short, optimally when you send your extruder/nozzle to HOME on the Z, the springs should be compressed most of the way to insure good tension is present. This alleviates the possibility almost all the time that the bed can come loose during the normal operation due to vibration and movements over time. The real fix there is as simple as adjusting the position of your Z sensor so that the optimal compression and tension on the springs is achieved.

Case Point: I rarely have to re-level the beds on multiple printers, sometimes going longer than a year and thats often after a nozzle change or other mechanical alteration. I even have a couple that have been in production for 2 years without having to do so.

If you prioritize the underlying reason you need a sensor you'll find alot less grief and even find yourself not even needing one. Simple as that. If you think a sensor will help you with a misdirected problem of bed adhesion, you are simply wrong. First layer adhesion and lay is a process you must learn, and once you do you wont give it a second thought.

Hope this clears a few things up and helps some people (especially you new folks) to understand that newer is not always necessary, needed, or recommended at times.