Ok, the thickness is because the default is OpenGL rendering on in LO and this makes svg equations too thick. However, tha size issue persists.
I have tried the second option in Windows 10: moved my configuration in AppData/Roaming/LibreOffice/ to a different directory, run LO Draw and installed TexMaths 0.46.2. The result is even more confusing. The svg mode again generates smaller equations than the png mode. What is even more disturbing is that the svg equations are now more thick compare to png, which looks as it should. When I put back my original configuration directory, the svg equations have correct thickness. They are smaller than...
This is weird!?! Could you please tell me how to check the macro code? I have just installed 0.46.2. over 0.46.1. using LO extension manager. The oxt files are binary.
This is interesting. I am using the latest LO 6.1.5.2 (Write and Impress) and I tested Texmaths 0.46.2 on both Ubuntu 18.04.2 and Windows 10. The size of equations is correct in the case of png rendering but too small in the svg mode. The behaviour is exactly the same as for Texmaths 0.46.1. Could someone else confirm that on the latest LO 6.1.5.2 the workaround in 0.46.2. does not function correctly or there is some specific problem on both of my systems.
I have noticed the same problem with TexMaths-0.46.1 after switching from LO 6.0.7 to 6.1.5 on Ubuntu 18.04.2. I was relieved, after seeing the solution here. I have tried TexMaths-0.46.2 from the link above, but unfortunately the incorrect scale in svg equations is still present. Maybe the problem cannot be solved so easily. I am willing to do more tests, but someone has to tell me what.