i think the issue with offset is the vcore given on low cpu usage which is too low.
try linx on 1 thread you will see what i mean.
for example me i normaly need about 1.38v for 4.8 ghz but when i was trying offset with ultra high llc with 1.41 on max vcore i was still not stable.
then i tryed linx on 1 thread and i noticed that my vcore could go at like 1.280v for 4.8 ghz
what worked for me to have a higher mini vcore on load but not too high max vcore is medium llc with higher offset.
Now my min vcore on load is 1.320v and my max on 8 thread is 1.4v.
yes its still a bit higher than my manual vcore,but i dont use apps fully loading my cpu like linx so im rarely at 1.4 v.
hope it helps