Yes it is. To install manually, you just need to run the installer, and install the tweaks to some other folder (like your desktop or documents or whatever) and then you can just drag and drop whatever you want. Just be sure to regenerate after.
@beta990 I'll test the new version today when I get the chance and let you know
EDIT
Okay, after testing the new beta version, player growth has been improved a bit. Players that should be growing at least a bit now are (such as Agger, Cissohko, Enrique etc.) But, some younger players are still growing a little too quick. Again, Suso grows 7 points overall, the first 3-4 after the first month. I understand he has a high potential (89) but he still shouldn't be growing quite as quick as that. IMO, he should have grown 7 points after around 1.75 seasons. Sturridge grew a little slower, but after a pretty lame performance over the season, he still outgrew his potential by 1. Again, at the form he was playing at, it should have taken around 2 seasons for him to reach this.
Transfers still need some work. There was actually 1 transfer on deadline day this time, but for £7 million. There should be a lot more deadline transfers. Also, over the period of January, hardly any transfers were really made, and of those that were, the most expensive was only around £8 million.
Finally, retirement again needs tweaking. Xavi and Pirlo dropped a lot for example. Xavi by 6 and Pirlo by 8. At most it should be 1-2.