Our demos score 90% and above in Google Desktop Page Speed with out using any paid plugin. We simply used Amazon LightSail (2 GB Ram, 1 Core Cpu), Lightspeed server with light speed cache. No other plugin or optimization technique was used. For CDN or reverse proxy we used Cloudflare. So by using similar or better hosting you should be able to achieve good page speed.
Point to note is, to showcase various features we need to make a page design long which sometimes reduce page speed score. So if you keep your page height to 5-6 sections then your site would have higher score and this is applicable for all types of sites and its not a limitation of Consultino.
Also, optimize site images, use webp to improve score.
Using static page cache would improve TTFB of your site and would increase score.
Always use better hosting. Hosting cost less than a cup of coffee and we see people cut costs on hosting and used to host multiple sites from shared hosting accounts which reduce page speed as all sites use same resource from that shared hosting account.
When we release a theme we test in major hosting networks and after getting satisfactory results, we release a theme, so please work above factors to improve page speed of your site.