you can buy frozen burgers that have cheese already in them, they in my opinion are a much better alternative.
I suspect if rustlers made a oven cooked variant of their product it be so much better, but microwave seems more fashionable due to the cooking speed, but microwave is not good for certain types of food.
It is incredible how variable quality of food can be.
Like frozen sausages that are oven cooked, there was a particular product I used to buy from tesco and they tasted so nice, the meat was full, and they were not watery and also not very fatty, the fat left in the oven tray was minimal. Then suddenly one week the product was replaced with another one on the tesco website, I suspect they changed suppliers to save costs, and the new one was horrible, about 5x the fat left in the oven tray after they were cooked, they were very watery, and sort of shrunk when cooked. A trend I noticed in lots of products is increased water conent over the years presumably to save costs.
Another one is burgers, some burgers are more filling than others, whilst some shrink when cooked and are watery.
Sandwich spreads, cheese and onion sandwich spread 10 years ago you could really taste the cheese and onions and it was a thick spread, now days if you buy the same spread from "any" supermarket (so they all using same supplier or same cost cutting techniques), they much more watery with weaker taste that feels artificial.
Pre packed sandwiches from tesco were repackaged in the past 2 months (probably changed supplier), the quality is noticeably down, again higher water content, they probably saving something like 5p per sandwich but profit is profit. When tesco reduced the sizes of their subs, but kept the quality I prefer that to just making the product taste like crap and been soggy.
I have worked for a food manufacturer and seen the sort of cost cutting that can go on, but sometimes it gets reversed when sales drop and/or complaints go up.