Yeah that’s understandable. One thing to keep in mind is that I don’t think they’re updating type tool very often—most of the dev resources are going to Fontlab 7 (the Mac version first). So type tool trails a bit.
Though with both type tool and glyphs mini, you can purchase an upgrade license rather than paying full price when you want to move up.
Another option to consider that is windows-only is: https://www.high-logic.com/font-editor/fontcreator though I haven’t used it myself. It seems the personal license would be sufficient for your needs.
I'm using High-Logic FontCreator for my conscript, which gives you a few options. If your inventory is the same as a preexisting abugida, then you can simply overwrite the relevant unicode characters. Create the font, install it, and switch input mode to the correct language.
If you have a different inventory, then you can use the program's support for OpenType ligatures to create a similar effect. This permits any multi-key input to be evaluated as a single character. Set your character's code point to the Unicode Private Use Area, and use the OpenType editor to add the keystroke input and character output. If you use this method to create fonts for Microsoft Word or other text editors, you may need to enable OpenType ligatures in settings.
As a final note, FontCreator isn't a free program. I find it to be the most reliable out of the ones I've tried, but there are free options out there like FontForge.
On Windows, I recommend FontCreator. I used to recommend FontLab for beginners but the last two versions are absolutely not suited to beginners. There are no good tutorials, the documentation is poor and the interface is impenetrable. FontCreator has a lot of YouTube tutorials available and plenty of automated featured to help you get started. The only thing that's missing if you want to go pro is interpolation for creating multiple weights but they're working on that.
No recommendations, as I rarely dabble in fonts these days, but a couple other options, in case you didn't know about them:
You might also consider Fontself if you're an Illustrator user. It's an Illustrator/Photoshop plugin that lets you make fonts right in AI. I've used it for some icon-fonts and such, more as a production tool than a design one, but it worked well enough for what I needed it for, and it's improving all the time.
If you're on Windows, there's also High-Logic FontCreator, which... I don't know much at all about. I had a version of it about 5 or 6 years ago, I think, but never did much with it. I know of it via their MainType font manager, which is one of the better ones for Windows font management.
Glyphs mini if you're on a budget, FontForge is your have no budget. FF is not very user friendly but quite powerful.
Other cheap options:
Font Creator is good for that, as evidenced by this here; it also addresses strokes. I should add that I use Font Creator as my main tool for font creation and I highly recommend it.
Fontcreator in terms of affordability but if money isn't an issue then Fontlab VI. I dunno exactly what the current build of fontcreator lacks that fl vi does but these two apps are your best bet for PC. Fontlab has cheaper alternatives too like fontographer geared toward beginners but clearly it's going to lack in features compared to FL VI.