Abusing inactivity?

I feel like I've been suffering these retarded -20, +15 LP gains whole season which reduces my will to play. Still I've somehow managed to keep in Challenger for 4 months now in a row, with only 1 drop due to decay. When I decayed, my gains were naturally too gently (about +25, -12) and that's why I managed to return to my old LP amount in just a week or so (from 60 to 460).

This decay seemed to have no negative impact for me, but just brough extra freelo since I had bad LP gains when my inactivity started, but after getting my LP back my gains were too great compared to what they were before.

Now I have once again worse LP rewards than I would like them to be so there's actually no point playing anymore. I could just let inactivity do the job again so I could refresh the gains for free and buy time. What I experienced so far, I'm pretty sure the system can be abused this way.

So, if you know you can get to a certain high rank, never do the mistake and start playing instantly when seasons start because it may get too exhausting. Instead, just wait to last month or if you have played, let your account be inactive.