That firewall is made out of LitePly. LitePly is excellent stuff for fuselage bulkheads and sides (when it's got great big lightening holes cut in it.)

Liteply doesn't stand compression very well. When you tighten down the motor mount bolts, the T-nuts put a lot of compression on 4 small areas of the LitePly. And the motor mount puts the same pressure on the front of that firewall.

It seems that the firewall isn't supported from it's centerline up. OK, it is, but it's by the balsa sheeted foam that forms the top front of the fuselage.

The firewall will benefit greatly from an additional layer of "real" plywood. Airply works great. It's hardwood and compression ain't no problem for it.

It's a sensible idea to sheet the front of that firewall with a layer of Airply (any LHS has it) to spread the support out over more of the firewall and to resist the compression of mounting the motor mount. And when you do that, drilling new holes will be needed anyway.