I'm not talking about whole house generators.
Have you read about circuit selectable transfer switches at all? They have external power inlets and can work with your existing generator. ID which circuits you want to work in an outage, buy a transfer switch big enough to fit that load, then bobs your uncle. Pick which of those circuits you want to power with your genny, then when the power comes back on, every other circuit in the house gets power.
Might not make sense for you to put one in now that you have your interlock setup, but if you decide to make changes in the future, think about changing over to a manual transfer switch setup.
You don't need utility power status with a selective transfer switch.
Order of operations with a transfer switch:
1. power goes out. whole house dark
2. get portable generator out and cut it on
3. plug generator into transfer switch power inlet
4. switch each circuit on the transfer switch from line-->off-->generator
Boom, now you have circuits being powered by the generator.
When the utility power comes back on, every other circuit in the house gets power, and the circuits you've switched to the generator are still on the generator. Now you disconnect.
1. switch each circuit on the transfer switch from generator-->off-->line
2. cut off generator
3. disconnect generator from transfer switch power inlet
4. put everything away
Reliance controls has a good reputation from what I have read. I have a 15a, 4 circuit manual transfer switch for my house that I am going to power with a Honda eu2200i portable on natural gas/propane. It's the smallest manual transfer switch they offer. Four circuits of lights and a fridge will be plenty to get us through a power outage in relative comfort.
https://www.electricgeneratorsdirect.com/power/reliance-controls-accessories.html
A manual transfer switch like the above is a little more expensive than an interlock kit, wire, and outlet to put a generator on a panel without backfeeding. With an interlock, you have to put stickers on the breakers you can/want to keep on, and you have no idea when the power comes back on without a "powerback" type of thing. Of course you could switch the interlock back to line power, but that's a hassle.
I did a lot of research with Dorian coming through our region recently. With effectively the same money, and a lot less hassle during an outage, I can get safe power to power my essentials with a manual transfer switch.
Final Edit:
For those wanting more detail, watch this video series from Reliance Controls. They are informative and concise.