It’s all going to come down to your manager. You shouldn’t be out there fighting for resources from other teams and arguing their relative priority. Your manager needs to be working within the new company to establish priorities and get the appropriate time, money, headcount, and resources in place to make these things happen. The platform team won’t automatically know your situation and it’s not really your place to drive it. Get your manager involved.
However, you have to watch closely to see how your management chain is handling the acquisition the great energy and enthusiasm they had for the startup might be completely gone now that they’ve been acquired. If they’re only sticking around long enough to cash in their earn-out provision, they may be completely uninterested in helping out. If this is the case, you probably aren’t going to get any happier in your current role.