The thing that's going to be the biggest determing factor of whether or not it runs nice & smooth on both desktops & tablets is the default game resolution. Seeing as you are doing a first person game you might be able to get away with using a default resolution of 1920x1080, but if you want to play it safe then I would recommend using 1280x720 instead.
Also I would highly recommend using XnConvert from the start to batch convert your png files into webp image format & import those into Visionaire Studio instead of the png files as webp image format tends to be up to 50% smaller than png.
Here's the
link to the wiki page I wrote that contains a link to XnConvert, as well as a small guide on how to set it up & use it.
Here's another
guide I wrote on how to create overlay interfaces & also how to split a single scene into 4 scenes - I don't know if the latter is viable for mobile/tablets as you are technically creating a scene that's 4x or higher than the default game resolution & forcing the camera position to the section you need it on, but it certainly helps keep the project organized by having all perspective views of a room in the same scene.
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