Ive been messing around with unity the past few hours and have come to find that with personal edition it is possible to change the splash screen, now whether Unity frowns upon this or not is not know at the time.
Navigate to the Data folder(Default for android on windows is: C:\Program Files\Unity\Editor\Data\PlaybackEngines\AndroidPlayer\Apk\assets\bin\Data).
Edit the splash.png image in whatever Image manipulation program you so chose.
OVERWRITE the old splash.png with the newly edited splash Image and thats it! Done!
Again im not aware if unity approves of this method or not but either way it works a treat.
Might be useful if the default splash is not conformant with the current branding guidelines in some older version? (I don’t think the 2017.2 version I have has the above)
“Frowns on” seems like an odd term in the context, I’d guess what would matter is whether you would be permitted to do so under the license agreement/s?
Changing the splash logo images or replacing them in any shape or form for personal is not permitted, but users can supply their own if using a license that supports it such as plus or pro.